JPH04211233A - Driving device for photographing optical system - Google Patents

Abstract

PURPOSE:To provide a camera with which the reduction of dimension is realized by arranging a motor for driving a photographing optical system in rational manner. CONSTITUTION:A driving device for a photographing optical system 3 is constituted of a motor 12 as driving device for the photographing optical system, supporting member 10 for supporting the photographing optical system and the motor, and the driving mechanisms 13, 14 and 15 for shifting the supporting member in the optical axis direction of the photographing optical system by the driving force of the motor.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for driving a photographing optical system of a camera.

0002

2. Description of the Related Art Conventionally, cameras have been proposed that include a motor and a drive mechanism that drives a photographing optical system using the driving force of the motor. In this type of camera, the motor is fixedly disposed within the camera body. The location is selected somewhere outside the photographing light flux emitted by the photographing optical system. However, the diameter of the light beam formed at a certain position between the exit end of the photographic optical system and the imaging surface generally increases as the photographic optical system is extended. It was necessary to take this into consideration when deciding where to place the motor. As a result, the arranged motor causes the camera to become larger in the direction perpendicular to the optical axis.

0003

SUMMARY OF THE INVENTION An object of the present invention is to provide a camera in which motors are arranged in a rational manner to achieve miniaturization.

0004

[Means for Solving the Problems] Accordingly, in the present invention, a photographing optical system drive device includes a photographing optical system (3, 26) and a motor (
12), a support member (10) that supports the photographic optical system and the motor, and a drive mechanism (12a) that displaces the support member in the optical axis direction of the photographic optical system by the driving force from the motor.
, 13, 14, 15).

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to the drawings. 1 to 3 each show a top view of an embodiment of the present invention. In each figure, a dustproof cover 2 and a photographing optical system 3 are provided on the front surface of a camera body 1. The dustproof cover 2 is movable in the left-right direction in the figure, and can be clicked in three positions: first and second open positions that expose the photographic optical system 3, and closed positions that shield it. The photographing optical system 3 is displaceable in the vertical direction in the figure, and is provided so that it can take two positions: an extended position and a retracted position.

In FIG. 1, the dustproof cover 2 is in a first open position, and the photographing optical system 3 is in an extended position protruding from the front surface of the dustproof cover 2. At this time, the photographing optical system 3 includes a sub-photographing optical system 26 (shown in FIG. 5), which will be described later, and which is inserted into the photographing light beam.
A synthetic optical system is constructed to achieve a focal length in the telephoto range. Therefore, it becomes possible to take pictures with a telephoto optical system. At this time, the indicator 2a points to the letter "T" on the camera body to make this visible.

In FIG. 2, the dustproof cover 2 is in a second open position displaced to the left from the first open position, and the photographic optical system 3 is retracted into the camera body 1 from the extended position. is in the retracted position. At this time, the auxiliary photographing optical system 26 is retreated from the photographing light beam, and the photographing optical system 3 has a focal length in a wide-angle region. Therefore, it becomes possible to take pictures with a wide-angle optical system. At this time, the index 2a is the letter "W" on the camera body 1.
This can be made visible by facing the

In FIG. 3, the dustproof cover 2 is in a closed position displaced to the left from the second open position, and covers the photographing optical system 3 in the retracted position. When the dustproof cover is in this closed position, an indicator 2a attached to the top surface of the dustproof cover 2 is attached to the top surface of the camera body 1 in order to make it visible from the top of the camera that photography is not possible. The characters “OFF”
” and facing each other.

Switches Sw1 and Sw2 are shown in a partially cutaway portion of the camera body in FIG. Both switches S
w1 and Sw2 are switched in opposite phases depending on the position of the dustproof cover 2, and are a motor 12 (described later) that displaces the photographing optical system 3.
(shown in FIGS. 4 to 6). The dustproof cover and both switches are interlocked by a rod 4 provided on the camera body so as to be movable in the vertical direction in the figure. One end of the rod 4 is attached to the dustproof cover 2 by the biasing force of the spring 5.
It can protrude into the sliding path on the inner surface of the dust cover 2, and protrudes only when the dustproof cover 2 is in the first open position shown in FIG. At this time, the switches Sw1 and Sw2 are turned OFF and ON under the action of the spring receiving collar 4a provided in the middle of the rod 4, respectively. Dust cover 2
When is displaced leftward from the first open position, the tip of the rod 4 is pushed against the inner surface of the dustproof cover 2, so the rod 4 is displaced upward in the figure, turning on switches Sw1 and Sw2.
, switch to OFF.

A switch Sw3 is shown in a partially cutaway portion of the camera body in FIG. The switch Sw3 turns OFF when the dustproof cover 2 is displaced to the left from the second open position.
The shutter control circuit 30 (shown in FIG. 6), which will be described later,
The shutter release is prohibited by cutting off the power supply to the camera. The dustproof cover and the switch Sw3 are interlocked by a rod 6 provided on the camera body so as to be movable in the vertical direction in the figure. One end of the rod 6 can protrude into the sliding path of the dustproof cover 2 by the biasing force of the movable piece of the switch Sw3, and is designed to protrude only when the dustproof cover 2 is in the first or second open position. It has become. At this time switch Sw3
are turned ON after the interference at the other end of the rod 4 is released. When the dustproof cover 2 is displaced from the second open position toward the closed position, the tip of the rod 6 is pushed against the inner surface of the dustproof cover 2, so the rod 6 is displaced upward in the figure and turns the switch Sw3 OFF. .

FIG. 4 shows a perspective view of the mechanical components of the photographic optical system drive device of this embodiment. In the same figure,
An aperture 10a through which a photographing light flux passes is provided in the center of the base plate 10 serving as a support member, and in front of the aperture 10a, an aperture/shutter device 11 and a photographing optical system 3, shown by dashed lines, are fixedly installed. . A motor 12 is fixedly installed on the upper back surface of the base plate 10, and its rotation axis is parallel to the base plate 10 (as shown in FIG. 5).
A bevel gear 12a (shown in FIG. 5) is fixedly installed at the tip. A bevel gear 13 pivotally supported by the base plate 10 meshes with this bevel gear 12a, and a gear 14 also pivotally supported by the base plate meshes with the spur tooth portion of this gear 13. A through hole is formed in the center of the gear 14, and a female thread is cut in the through hole with the rotation center of the gear 14 as the axis. A male thread cut on the guide shaft 15 is screwed into this female thread. The guide shaft 15 extends in the optical axis direction, and its base end is fixed to the substrate 1a of the camera body, and its tip is loosely fitted into the through hole of the base plate 10 and then screwed into the female thread of the gear 14. It matches. Two guide shafts 16 and 17 extending in the optical axis direction are also implanted in the substrate 1a. The guide shaft 16 passes through a through hole 10c of an overhang 10b protruding from the back surface of the base plate 10 and a through hole 10d of the base plate 10 in a loosely fitted state. In the middle of the guide shaft 16 is a spring receiving collar 1.
6a is fixedly provided, and a spring 18 is provided between the collar portion 16a and the overhang portion 10b. This spring 18 is
The base plate 10 is pressed in the direction of the substrate 1a via the projecting portion 10b to remove backlash occurring at the screwed portion between the gear 14 and the guide shaft 15. The guide shaft 17 has a long hole 1 in the base plate 10.
It penetrates through 0e with a loose fit. With this configuration, when the motor 12 rotates, the base plate 10, the photographing optical system 3 fixed thereto, and the diaphragm/shutter device 11 are guided by the three guide shafts 15 to 17 and moved to the extended position and the retracted position. displacement in the optical axis direction.

A printed circuit board 19 is fixedly mounted on the right side of the base plate 10. Conductor lands 19a to 19c are provided on the surface of this printed circuit board 19, and three sliding contacts 20 to 22 fixedly attached to the camera body can slide into these, respectively. The sliding contact 20 and the conductive land 19a constitute a switch Sw4, the sliding contact 21 and the conductive land 19b constitute a switch Sw5, and the sliding contact 22 and the conductive land 19c constitute a switch Sw6. When the photographic optical system 3 is in the retracted position, the switch Sw3 is in the extended position, and the switch Sw5 is in the extended position.
are turned OFF when they are between the retracted position and the extended position. The switches Sw4 and Sw5 function as limit switches, and cut off the power supply to the motor 12 when the photographic optical system 3 is displaced to the retracted position or the extended position. Switch Sw6
In this case, the photographing optical system 3 is located at a position intermediate between the above two positions,
This switch is used to cut off the power supply to the shutter control circuit in order to prevent the shutter release from being performed when the object image cannot be formed on the film surface.

The film 23 is disposed behind the base plate 10. FIG. 5 is a front view of the sub-photographing optical system insertion/removal mechanism provided on the back surface of the base plate 10. In the figure, the base plate 10
A reduction gear train 24 and a holder 25 are pivotally supported on the back surface of the camera, and a sub-photographing optical system 26 is held in the holder 25. The input gear 24a of the reduction gear train 24 meshes with the spur tooth portion of the bevel gear 13, and
The final gear 24b and the holder 25 are coaxial and connected via a torsion spring 27.

The reduction ratio of the reduction gear train 24 is set as follows. That is, when the photographing optical system 3 is in the extended position, the sub-photographing optical system 26 is placed in the insertion position (shown by a solid line) inserted into the photographing light beam, and when the photographing optical system 3 is displaced to the extended position, the sub-photographing optical system 26 is inserted into the photographing light beam. 26 is swung to a retracted position (indicated by a two-dot chain line) where it is retracted from the photographing light beam.

The sub-photographing optical system 26 constitutes a composite optical system with the photographic optical system 3 in the extended position, and changes the focal length to a telephoto range. FIG. 6 shows a motor control circuit which is an electrical component of the photographing optical system drive device of this embodiment. In the figure, the motor 12 is driven by three power supply paths.

The first path is from the positive electrode of the power source E to the switch S.
w4-Switch Sw1a-Motor 12-Switch Sw1
b - This is the path of the negative electrode of the power source E. By supplying power through this path, the motor 12 rotates, displacing the photographing optical system 3 to the retracted position and displacing the sub-photographing optical system 26 to the retracted position. The second path is the positive electrode of power supply E - switch Sw5 - switch Sw2a - motor 12 - switch S
w2b - This is the path of the negative electrode of the power source E. By supplying power through this path, the motor 12 rotates in the opposite direction to that in the first path, displacing the photographing optical system 3 to the extended position and displacing the auxiliary photographing optical system 26 to the insertion position. .

Here, the switches Sw1a and Sw1b are semiconductor switches controlled by the switch Sw1, and are switched in the same phase as the switch Sw1.
w2a and Sw2b are semiconductor switches controlled by the switch Sw2, and are switched in the same phase as the switch Sw2. The third path is a path that connects the automatic focus adjustment/shutter control circuit 30 and the motor 12, and the output of this control circuit causes the motor 12 to be rotated in the forward and reverse directions to move the photographing optical system to the retracted position or the extended position. moves back and forth in the direction of the optical axis to automatically adjust the focus.

[0018] In the power supply path of this control circuit 30, switches Sw3 and Sw6 connected in series are inserted. The switch Sw3 is turned off when the dustproof cover 2 is in the intermediate position between the second open position and the closed position and in the closed position. The switch Sw6 is turned OFF when the photographing optical system 3 is at the intermediate position between the extended position and the retracted position (when the sub photographing optical system 26 is at the intermediate position between the retracted position and the inserted position). These prevent the shutter release from being performed when the photographing optical systems 3, 26 and the dustproof cover 2 are in positions inappropriate for photographing.

Next, the operation of this embodiment will be explained according to Table 1 below. Table 1 shows the position of the dustproof cover 2 and the photographic optical system 3.
, 26 focal lengths, and the state of each switch are shown in the order in which the dustproof cover 2 is reciprocated between the first open position shown in FIG. 1 and the closed position shown in FIG. 3. has been done.

[0020]

[Table 1]

(1) Phase 1 When the dustproof cover 2 is in the first open position, the switches Sw1 and Sw2 are in the OFF and ON states, respectively, as shown in FIG.
1b, Sw2a and Sw2b are also in the OFF and ON states, and the switch Sw3 is in the ON state. At this time, the photographing optical system 3 is in the extended position, so the switches Sw4 to Sw6 are turned ON, OFF, and OFF, respectively, as shown in FIG.
It is in the ON state. Switches Sw1a and Sw1b are OFF
F, the first path is not formed and the switch S
Since w5 is OFF, the second path is not formed either. Therefore, the photographing optical system 3 is in the extended position, and the sub-photographing optical system 26 is
Since each of the two remains stationary at the insertion position, a synthetic optical system is constructed, and its focal length is in the telephoto range. Also, since switches Sw3 and Sw6 are both ON, automatic focus adjustment and
The shutter control circuit 30 is in an operable state, and automatic focus adjustment via the third path is possible, allowing photographing with a telephoto optical system.

(2) Phase 2 When the dustproof cover 2 is in the intermediate position between the first open position and the second open position, the rod 4 in FIG. 1 is pushed upward in the figure by the dustproof cover 2, and the switch Sw1 is , Sw2 are each ON
, switches to the OFF state, so switch Sw1a・
Similarly, Sw1b, Sw2a, and Sw2b are turned on and off. The switch Sw4 remains ON. Since the switches Sw1a, Sw1b, and Sw4 are ON, the first path is formed and the motor 12 is started. Therefore, the photographing optical system 3 begins to be displaced from the extended position toward the retracted position, and the sub-photographing optical system 26 begins to be displaced toward the retracted position. At this time, since both the photographing optical system 3 and the sub-photographing optical system 26 are in the middle of displacement, their focal lengths are indefinite. Since the photographing optical system 3 is located between the extended position and the retracted position, the switch Sw6 shown in FIG. automatic focus adjustment becomes impossible.

(3) Phase 3 Even if the dustproof cover 2 reaches the second open position, the switch Sw
1 and Sw2 do not change from the state of phase 2, so the states of switches Sw1a and Sw1b and Sw2a and Sw2b also do not change. However, when the photographing optical system 3 reaches the retraction position, the switches Sw4 to Sw6 shown in FIG. 4 are in the OFF, ON, and ON states, respectively. Since the switch Sw4 is OFF, the first path is cut off and power supply to the motor 12 is stopped. Therefore, since the photographing optical system 3 is stationary at the retracted position and the sub-photographing optical system 26 is stationary at the retracted position, the photographing optical system is composed only of the photographing optical system 3, and its focal length is in a wide-angle range. Also switch Sw
Since both 3 and Sw6 are ON, the automatic focus adjustment/shutter control circuit 30 is in an operable state, and automatic focus adjustment and photographing using the wide-angle optical system are possible.

(4) Phase 4 Even when the dustproof cover 2 reaches the intermediate position between the second open position and the closed position, the switches Sw1 and Sw2 remain in the same state as in phases 2 and 3, so the switch Sw1a remains unchanged.・Sw
The states of 1b, Sw2a and Sw2b do not change either. Therefore, the photographing optical system 3 remains stationary at the retracted position, and the sub-photographing optical system 26 remains stationary at the retracted position. At this time, the switch Sw3 is turned OFF, so the automatic focus adjustment/shutter control circuit 30 becomes inoperable, and photography becomes impossible.

(5) Phase 5 Phase 4 except that the dustproof cover 2 reaches the closed position
It's no different. (6) Phase 6 Same as Phase 4. (7) Phase 7 Same as Phase 3.

(8) Phase 8 When the dustproof cover 2 reaches the first open position, the rod 4 is released from the interference of the dustproof cover 2, as shown in FIG. 1, and is pushed downward in the figure by the biasing force of the spring 5. and switch Sw1,
Sw2 is switched to OFF and ON states, respectively. As a result, switches Sw1a/Sw1b, Sw2a/Sw
2b is also turned OFF and ON in the same way. Switch Sw
5 remains ON. Switches Sw2a, Sw2b,
Since Sw5 is ON, the second path is formed, and the motor 12 begins to rotate in the opposite direction to that in phase 2. Therefore, the photographing optical system 3 moves from the retracted position to the extended position,
The sub-photographing optical systems 26 each begin to be displaced from the retracted position toward the inserted position. At this time, since both the photographing optical system 3 and the sub-photographing optical system 26 are in the middle of displacement, their focal lengths are indefinite. When the photographing optical system 3 is located between the retracted position and the extended position, the switch Sw6 shown in FIG. 4 is turned OFF, and the automatic focus adjustment/shutter control circuit 30 becomes inoperable, making photographing impossible. .

(9) Phase 9 Same as phase 1.

[0028]

As described above, the photographic optical system drive device of the present invention includes a photographic optical system, a motor, a support member that supports the photographic optical system and the motor, and a driving force for supporting the photographic optical system and the motor. and a drive mechanism that displaces the member in the optical axis direction of the photographing optical system. According to this drive device, even if the photographic optical system is displaced, the distance between the optical system and the motor does not change and is always constant, so the diameter of the photographic light beam does not increase but decreases as the photographic optical system moves out. Therefore, the camera can be made smaller than the conventional example in which the motor is fixedly disposed within the camera body.

[Brief explanation of the drawing]

FIG. 1 is a top view of an embodiment of the present invention.

FIG. 2 is a top view of the same embodiment.

FIG. 3 is a top view of the same embodiment.

FIG. 4 is a perspective view of the drive mechanism of the photographing optical system of the same embodiment.

FIG. 5 is a front view showing an insertion/removal mechanism of the sub-photographing optical system of the same embodiment.

FIG. 6 is a circuit diagram of a motor control circuit for displacing the photographing optical system in the same embodiment.

[Explanation of symbols of main parts]

Claims (1)

[Claims] 1. A photographic optical system, a motor, a support member that supports the photographic optical system and the motor, and a drive that displaces the support member in the optical axis direction of the photographic optical system by a driving force from the motor. What is claimed is: 1. A photographing optical system drive device comprising: