JP2600639B2 - camera - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bifocal camera having a photographing lens capable of changing a focal length by inserting a sub optical system on a photographing optical axis in conjunction with extension of a main optical system, and more particularly to a main optical system. And a bifocal camera provided with an aperture / shutter immediately after the camera.

[0002]

2. Description of the Related Art A so-called bifocal camera capable of changing a focal length by extending a main optical system of a photographing lens forward and inserting a sub lens on an optical axis behind the main optical system is disclosed in, for example, JP-A-52-76919, JP-A-54-3
No. 3027 and Japanese Patent Application Laid-Open No. 58-202431. In the patent publications of these conventionally known bifocal cameras, there is no mention of a shutter for controlling exposure, but a proposal for such a shutter has already been disclosed in JP-A-59-19926. Have been.

However, in a known bifocal camera equipped with a shutter, a feed-out mechanism for focusing is provided around the main optical system, and a shutter driving mechanism and a diaphragm shutter are provided immediately after the main optical system. A blade is provided, and a sub-optical system is inserted behind the aperture / shutter blade. The structure of the shutter drive mechanism is extremely complicated, requiring a long time and experience for assembly work. Further, since the outer cylinder surrounding the main optical system and the shutter device is formed in a square cylindrical shape so as to also surround the lens frame of the sub optical system located at the retracted position outside the optical axis, there is no useless space inside the outer cylinder. In addition, there is a drawback that the outside of the outer cylinder must be further covered with a cover of a square cylinder in order to light-tightly seal the outer cylinder from the camera body. Also,
In the conventionally known bifocal camera including Japanese Patent Application Laid-Open No. 59-19926, no consideration is given to a lens barrier for protecting the main optical system.

[0004]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned drawbacks of the conventional bifocal camera, and incorporates a lens barrier and a shutter drive unit in a lens barrel that moves in the optical axis direction during focal length conversion. Accordingly, an object of the present invention is to provide a bifocal camera having good assembling workability and operability.

[0005]

SUMMARY OF THE INVENTION The present invention provides an optical system (6), and a lens barrel (6, 14, 16) that holds the optical system, is capable of moving back and forth in the optical axis direction, and is at least retractable to a storage position. A camera cover (2) having an opening through which the lens barrel can move forward and backward,
A protection member (28, 29) that can open and close the front surface of the optical system with at least two opening / closing members so that the protection member (28, 29) is positioned behind the frontmost surface of the lens barrel portion (6, 14, 16). (6, 14, 16), and when the lens barrel (6, 14, 16) is in the storage position, the lens barrel (6, 14, 16) is located behind the forefront of the camera cover (2). The technical point is that they are arranged.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings. 1 and 2 are sectional views showing an embodiment of the present invention. FIG. 1 shows a housed state in which a lens barrier is closed.
FIG. 2 shows a telephoto state in which a sub optical system is inserted on the optical axis of the main optical system. FIG. 3 is an enlarged sectional view of a sub lens holder which forms a part of the configuration of the embodiment shown in FIG. 4 and 5 are cross-sectional views taken along lines AA, BB, and CC of FIG. 1, respectively. FIG.
In FIG. 2 and FIG. 2, the camera body 1 is covered with an exterior case 2, and an upper portion 1A of the camera body 1 is provided with a distance detecting device including a light projecting lens and a light receiving lens (not shown), a viewfinder optical system, and the like. On the front surface of the main optical system 3 of the taking lens, a lens barrier 2 described in detail later is provided.
8 and 29 are provided so as to be openable and closable, and a sub optical system 4 is provided behind the main optical system 3 so as to be insertable into and removable from the photographing optical axis. Further, on the upper surface of the outer cover 2, a focal length selection member 5 operated for switching the focal length of the photographing lens and opening and closing the lens barriers 28 and 29 is slidably provided. As shown in FIG. 7, the focal length selecting member 5
A, when the index 5A matches the symbol “OFF” provided on the upper surface of the outer cover 2, the lens barrier 28,
29 is opened, and when the index 5A matches the wide-angle symbol "W", the lens barriers 28 and 29 are opened and the main optical system 3 is opened.
Only by this, a short focal length state (hereinafter, referred to as a “wide angle state”) in which photographing is possible is achieved. When the index 5A matches the telephoto symbol "T", an optical system moving mechanism, which will be described in detail later, operates, and the main optical system 3 is extended forward, whereby the sub optical system 4 is moved to its main optical system. 3 and a long combined focal length state (hereinafter referred to as a “telephoto state”) of the main optical system 3 and the sub optical system 4. The focal length selection operation member 5 includes a control circuit that controls a reversible motor M that is a driving source for moving the main optical system 3 in the optical axis direction and displacing the sub optical system 4 in the direction perpendicular to the optical axis. A switch device 57 for transmitting a focal length switching signal is linked (see FIG. 7).

The main lens frame 6 for holding the main optical system 3 is fixed to a shutter substrate 7 with a bayonet 7A and small screws 8A. The shutter substrate 7 is, as shown in FIG.
A barrier board 9 (see FIG. 1) for supporting a lens protection cover device, which will be described in detail later, is fixed to the base plate 10 by three small screws 8B and three small screws 8C via three projecting feet 9A. Have been. An aperture / shutter blade 12 driven by a step motor 11 is provided between the base plate 10 and the shutter substrate 7. Further, an optical system driving device (see FIG. 8), which will be described later, driven by a reversible motor M is provided on the back surface of the base plate 10, and the optical system moving mechanism moves the base plate 10 along the optical axis. The sub optical system holder 13 supporting the sub optical system 4 is displaced in a direction perpendicular to the optical axis.

As shown in FIG. 3, the sub optical system holder 13 has a sub lens frame 13A for holding the sub optical system 4, an inner frame tube 13B screwed to the sub lens frame 13A, and an inner frame tube 1A.
It comprises an outer frame 13C supporting 3B, and a compression spring 13D provided between the flange of the sub lens frame 13A and the inner frame tube 13B. Since the sub-lens frame 13A is screwed into the inner frame tube 13, the sub-optical system 4 is rotated as shown in FIG. 2 by rotating the sub-lens frame 13A against the urging force of the strong compression spring 13D. When the optical system 3 is inserted so as to coincide with the optical axis of the optical system 3, the distance between the two optical systems 3 and 4 can be adjusted, whereby the combined focal length can be easily set to a predetermined value. .

A front ring 14 is provided on the front surface of the barrier substrate 9 fixed to the base plate 10.
Are supported by two pillars 15A and 15B (see FIG. 5) implanted in the fin. One end of an outer cylinder 16 that covers the barrier substrate 9 and the outer periphery of the front ring 14 is fixed to the base plate 10 by small screws 17 as shown in FIG. 6, and the other end is fitted to the front ring 14 as shown in FIG. I agree. Also, a black soft packing 18A is provided between the barrier substrate 9 and the outer cylinder 16, and the outer cylinder 1
The outer periphery of 6 is light-tightly sealed by a double light blocking member 18B provided at the front end of the camera body 1. Front ring 1
Reference numeral 4 denotes a front substrate that supports the lens protection cover device together with the barrier substrate 9. As shown by the broken line in FIG. 5, the lens barrel opening 14A provided at the center of the front ring 14 is in the XX axis direction (the film opening 1B) about the optical axis.
Is formed in a substantially hexagonal shape in which four corners of a rectangle that is longer in the Y-axis direction (short side direction of the film opening 1B) and longer in the Y-axis direction (in the short side direction of the film opening 1B) are rounded off in an arc around the optical axis.

A ring gear 19 is rotatably supported on the back side of the front ring 14, and the ring gear 19 has a first segment gear portion 19A and a second segment gear portion 180 ° apart from each other as shown in FIG. 19B are formed symmetrically about the optical axis. Further, a third segment gear portion 19C having a tooth form outer periphery slightly smaller than the tooth form outer periphery of the pair of segment gear parts 19A and 19B is formed on the outer periphery of the ring gear near the first segment gear part 19A. The first pinion gear 20 meshing with the first segment gear portion 19A is formed integrally with the first rotating lever 21, and a flange portion 20A is formed integrally on one side surface of the tooth row. Also, the second segment gear portion 19
B and the second pinion gear 22 meshing with the second rotation lever 2
3, and a flange portion 22A is integrally formed on one side surface of the tooth row. The first pivoting lever 21 has a first pinion gear 20, and the second pivoting lever 23 has a base 21A, 23A formed in a key shape so as to enable plastic molding integrally with the second pinion gear 22, respectively. I have. Further, the first pinion gear 20 and the first rotary lever 21 integrally formed with the barrier board 9 and the front ring 14 are respectively connected to the second pinion gear 22 and the second rotary lever 23 via support shafts 24 and 25, respectively. The ring gear 19 is further prevented from moving in the thrust direction (rightward in FIG. 1) by the flange portions 20A and 22A. First pivot lever 21
And the free end of the second rotating lever 23,
The first barrier 28 and the second barrier 29 are held so as to be freely rotatable via 6 and 27. The first barrier 28 and the second barrier 29 are formed in arc portions 28a, 29a having an outer circumference substantially equal to the inner radius of the outer cylinder 16, and when the lens barriers 28, 29 are opened, the arcs are formed respectively. The portions 28a and 29a contact the inner peripheral surface of the outer cylinder 16,
At this time, the straight entrances (opening edges) 28b, 29b opposite to the arcs 28a, 29a are configured to be parallel to the long side direction (XX axis direction) of the film opening 1B. ing. The entrances 28b and 29b are provided with the lens barrier 2
When the shutters 8 and 29 are closed, as shown in FIG. 5, they contact each other on the optical axis. At this time, the lower end 28c of the first barrier 28 abuts the support 15A, and the upper edge of the right end of the second barrier 29. 2
Reference numeral 9c abuts against a limiting pin 30 implanted in the barrier substrate 9, so that the directions of the gates 28b and 29b are the same as the XX axis direction at the time of opening.

Further, as shown in FIG. 4, a light receiving window 35 is provided on the front ring 14, and a light receiving element 36 is provided behind the light receiving window 35 (to the right in FIG. 4). I have. The light receiving window 35 is sealed with a dust-proof transparent plastic plate 37. The light receiving element 36 is accommodated in a light receiving element holder 39 provided on a shutter control circuit board 38 provided between the barrier substrate 9 and the shutter substrate 7 as shown in FIG. The shutter control circuit board 38 is fixedly mounted on the shutter board 7 with an appropriate gap. The shutter control circuit board 38 surrounds and surrounds the main lens frame 6 in addition to the light receiving element holder 39 on the shutter control circuit board 38. , A step motor 11 for driving the aperture / shutter blade 12 and a transistor T for controlling the same.
_r1, T _r2, photometric IC95 below, capacitor C _1, C
Control circuit devices such as ₂ are provided.

On the other hand, a third pinion gear 40 meshing with the third segment gear portion 19C of the ring gear 19 is supported by an interlocking shaft 41 and formed integrally with the flange portion 40A as shown in FIG. This flange portion 40A is
Together with the flange portion 20A of the pinion gear 20 and the flange portion 22A of the second pinion gear 22, the ring gear 19 is configured to prevent movement in the thrust direction (rightward in FIG. 4). An interlocking shaft 41 supporting the third pinion gear 40 is provided with a bracket 44 fixed on the back surface of the base plate 10.
And one end thereof is rotatably supported by the front ring 14 as shown in FIG. The other end of the interlocking shaft 41 penetrates the bracket 44 to integrally support the cam member 42 on the rear side as shown in FIGS. The cam member 42 has a cam surface 42A inclined with respect to the moving direction of the base plate 10, and is urged by a torsion coil spring 43 to rotate counterclockwise in FIG. When the lens barriers 28 and 29 are opened and come into contact with the inner surface of the outer cylinder 16 and when the lens barriers 28 and 29
9 when closed and in contact with each other.

The sliding plate 50 for rotating the cam member 42 includes
It is guided by a guide pin 51 implanted in the camera body 1 so as to be slidable up and down in FIG. The sliding plate 5
An engagement protrusion 52 that can be engaged with the cam surface 42A of the cam member 42 when the base plate 10 is retracted as shown in FIG. I have. The focal length of the sliding plate 50 is via an interlocking plate 54 urged upward in FIG. 7 by a tension coil spring 53 and a cam plate 56 which engages a sliding pin 55 implanted in the interlocking plate 54. It is linked with the selection operation member 5. The cam plate 56
As shown in FIG. 7, an upper edge 56B and a lower edge 56C having a step above and below the cam surface 56A are formed, and the index 5A of the focal length selection operation member 5 is set to the telephoto symbol "T" and the wide-angle symbol " When "W" is indicated, the lower edge 56C is engaged with the slide pin 55, and the engagement projection 52 of the slide plate 50 is placed outside the track along the optical axis of the cam surface 42A of the cam member 42. However, when the focal length selection operation member 5 is moved to the lower right in FIG. 7 so that the index 5A indicates the symbol “OFF”, the sliding pin 55 is moved by the urging force of the extension coil spring 53 to the cam surface 56A.
To move upward to engage with the upper edge 56B. The upward movement of the sliding pin 55 causes the engaging projection 52 of the sliding plate 50 to move upward to engage with the cam surface 52A of the cam member 42, and to twist the interlocking shaft 41 together with the cam member 42 to rotate the coil spring. It is configured to rotate clockwise in FIG. 7 against the biasing force of 43.

On the other hand, the base plate 10 and the sub lens holder 13
A motor control circuit 59 that operates based on signals from a switch device 57 interlocked with the focal length selection operation member 5 and an automatic focus adjustment distance detection device 58 provided in the camera body 1. Is controlled via In this case, the operation of the motor drive for focus adjustment is started by pressing a release button (not shown). However, the focal length is switched by driving the motor by operating the focal length selecting operation member 5 irrespective of the pressing of the release button. At this time, the base plate 10 is extended beyond the closest distance position in the wide-angle state or extended beyond the infinity position in the telephoto state by the switching signal of the switch device 57, during which the sub-optical disk is moved. The system 4 is configured to insert on or exit from the optical axis.

FIG. 8 shows the base plate 10 and the sub lens holder 1.
FIG. 4 is a perspective view of the base plate 10 viewed from the back side to show a driving mechanism for driving the base plate 3. The reversible motor M is fixedly mounted on the upper rear surface of the base plate 10, and its rotation is transmitted to a spur gear 62 integral with another bevel gear via a bevel gear 61 of a reduction gear head 60. Drive gear 63 meshing with this spur gear 62
Is rotatably supported by the base plate 10, and a feed screw shaft 64 fixed to the fixed portion of the camera body 1 and extending in the optical axis direction is screwed to a female lead screw provided at the center thereof. .
On the other hand, the rotation of the spur gear 62 is transmitted to the cam gear 66 via the reduction gear train 65. A front cam 67 (see FIG. 2) is provided on the surface of the cam gear 66.
The handle 13E of the auxiliary lens holder 13 is urged by a compression coil spring 68 so that the handle 13E is pressed against the arm. The front cam 67 according to the rotation of the reversible motor M for switching the focal length
When the is rotated, the sub-lens holder 13 is displaced rightward in FIG. 1 along the optical axis in accordance with the cam shape of the front cam 67, and subsequently rotated clockwise in FIG. Then, when the sub optical system 4 moves on the photographing optical axis, the sub optical system 4 is displaced leftward along the optical axis and
3B (see FIG. 3) is inserted into the circular step portion 10A of the base plate 10 as shown in FIG. 2, and the sub optical system 4 is configured to be fixed on the optical axis.

A notch groove 10C is provided on the left side surface (right side surface in FIG. 6) of the base plate 10 in FIG.
A first guide shaft 70 fixed to the fixed portion of the camera body 1 and long in the optical axis direction is fitted into C, and the base plate rotates around the feed screw shaft 64 even when the drive gear 63 rotates. It is configured so that there is no. As shown in FIG. 8, a bracket 44 fixedly provided on the back surface of the base plate 10 is provided with a protruding interlocking column 71 extending in the axial direction, and a through-hole provided on an end face of the interlocking column 71 is provided. Hole 71a and base plate 1
The second guide shaft 72 fixed to the fixed portion of the camera body 1 and extending in the optical axis direction passes through the through hole 10b (see FIG. 6) provided in the camera body 1. The base plate 10 is held perpendicularly to the photographing optical axis by the interlocking support column 71 and the second guide shaft 72, and is configured to move in parallel back and forth along the optical axis according to the rotation of the reversible motor M. Have been. A rack 73 is provided on a side surface of the interlocking support 71, and the rack 73 is provided.
The pinion 74 meshing with 3 is linked to a not-shown shooting distance display device, a distance detection device, and a finder magnification conversion mechanism.

The base plate 10 and the camera body 1 moving in the direction of the optical axis are bridged by a flexible printed board 75 which is bent in a waveform as shown in FIGS. The reversible motor M on the base plate 10, the step motor 11 on the shutter control circuit board 38, and the light-receiving element 36 for the exposure meter
It is connected to an electric device such as a focus detection circuit device and an exposure value calculation circuit device on the side.

FIG. 9 is a perspective view showing the construction of a diaphragm / shutter and its driving unit. Shutter blade for combined use of aperture 1
2 is composed of two diaphragm blades, and each diaphragm blade 1
2A and 12B are 2 planted on the back surface of the shutter substrate 7.
It is rotatably supported by a pin 80 of the book. Further, a blade holding plate 81 is fixed on the shutter substrate 7 as shown in FIG. 1 with a slight gap from the back surface of the shutter substrate 7. Also, the respective aperture blades 12A, 12B
The drive pin 82 passing through the elliptical hole 12A provided in the
Implanted in an arm 84A of a sector gear 84 rotatably supported on a pin shaft 83 fixed to the shutter substrate 7,
When the drive pin 82 rotates clockwise about the pin shaft 83 in FIG. 9, the shutter blade 12 is configured to be opened to a diaphragm diameter corresponding to the rotation angle. The pinion 85 meshing with the sector gear 84 is supported at one end of a rotating shaft 87 that penetrates the shutter board 7 and the shutter control circuit board 38, and the other end of the rotating shaft 87 is provided with a rotor 88 of the step motor 11. .

The step motor 11 includes a permanent magnet rotor 88 magnetized to four poles, a pair of stators 90A and 90B around which coils 89A and 89B are wound, and a motor cover 91 surrounding these. Stator 90
A and 90B are arranged symmetrically with respect to the rotor 88 as shown in FIG. The motor cover 91 surrounding the main lens frame 6 has a substantially semicircular shape. This stepping motor 11 is similar to that of FIG.
As shown in the figure, the transistor Tr _{r1 is disposed} at a position on the shutter control circuit board 38 opposite to the first barrier 28 when the lens barrier is opened with the barrier substrate 9 interposed therebetween.
T _r2, IC 95 and the like for metering is disposed at a position on shutter control circuit board 38 facing the second barrier 29 when it is opened.

FIG. 10 is a block diagram of an electric system for operating the step motor 11. The subject brightness detected by the light receiving element 36 such as a milliphotodiode (SPD) is digitized by the photometric IC 95 and sent to the arithmetic circuit 96. On the other hand, a digitized film sensitivity value signal from a film sensitivity value detection device 97 for detecting a code indicating a film type and a film sensitivity value provided in the film cartridge is also sent to the arithmetic circuit 96 and stored. From the subject luminance signal and the film sensitivity signal, the arithmetic circuit calculates an aperture value and a shutter speed value based on a predetermined program, and sends the calculated exposure value to the driving IC 98. The stepping motor 11 is controlled by a pulse signal from the driving IC 98, and operates as a program shutter that opens and closes according to a predetermined combination of the calculated aperture value and the shutter speed value. Have been. in this case,
By changing the magnetization direction of the stators 90A and 90B of the step motor 11 alternately to move the magnetic field, the rotor 88 can be rotated forward or forward.

As shown in FIG. 4, a contact 97A for detecting a film information code such as a film sensitivity value provided on the surface of the film cartridge projects from the side wall of the film cartridge room 1C of the camera body 1. Is provided. Of the detection signals detected by the contact 97A, the film sensitivity value signal is a film sensitivity detection device 97.
, And sent to an arithmetic circuit 96 (see FIG. 10) provided on the camera body 1 side. A pulse signal from the driving IC 98 for controlling the step motor 11 is transmitted from the camera body 1 to the step motor 11 via the flexible printed circuit board 75. Further, the patrone chamber 1C, the film take-up chamber 1D and the film aperture 1B are sealed by a known back cover 99 as shown in FIGS. 1 and 3, and the back cover 99 when a film patrone (not shown) is loaded. When the film cartridge is pressed by the closing operation, the contact 97A is provided so as to be in contact with the film information code portion so as to be pressed against the film information code portion.

Next, the operation and operation of the embodiment configured as described above will be described. When the lens barriers 28 and 29 are closed as shown in FIGS. 1 and 5, the base plate 10 is retracted, and the outer cylinder 16 is substantially housed in the outer case 2 on the camera body side. In this case, since the outer cylinder 16 containing the lens barriers 28 and 29, the main optical system 3, and the stepper motor 11 for driving the shutter is formed in a circular cross section, the gap between the outer cylinder 16 and the camera body 1 is reduced. Light entering the inside of the camera from between is easily and completely blocked by the double light-blocking member 18B provided at the front end of the camera body 1, and the outer cylinder 16 and the main optical system 3 are connected as shown in FIG. Even if the light is greatly squeezed out in the optical axis direction, the light does not enter the inside.

Also, as shown in FIG. 1, the lens barriers 28, 29
In the closed state, the focal length selection operation member 5 (FIG. 7)
Is located at a position where the index 5A matches the symbol "OFF" (hereinafter referred to as "OFF position"), and the sliding pin 55
Is engaged with the upper edge 56B of the cam plate 56, and the engaging projection 52 of the sliding plate 50 is connected to the cam surface 42A of the cam member 42 fixed to one end of the interlocking shaft 41 interlocking with the lens barriers 28 and 29.
As shown in FIG. On the other hand, the sub optical system 4 is located at a retracted position outside the photographing optical axis as shown in FIGS.

FIG. 11 shows a focal length selection operation member 5, an engagement protrusion 52, a cam member 42, and lens barriers 28 and 29.
5A is a diagram illustrating a state in which the focal length selection operation member 5 is at an OFF position, and FIGS. 5B and 5C are diagrams illustrating the focal length selection operation member 5 at a wide angle position. The state at the time of moving to the telephoto position is shown. Hereinafter, the operation of the interlocking mechanism of the lens barriers 28 and 29 and the driving mechanism of the photographing lens optical system will be described with reference to FIG.

In FIG. 11, the focal length selecting operation member 5
Is in the OFF position, the lens barriers 28 and 29 are open as shown in FIG. When the focal length selection operation member 5 is moved from this state to the wide angle position (the position indicating the symbol "W"), the cam plate 56 moves to the left in FIG. 7, and the sliding pin 55 moves along the cam surface 56A. And descends to engage the lower edge 56C. The lowering of the sliding pin 55 causes the interlocking plate 54 to slide downward against the urging force of the tension coil spring 53, and the sliding plate 50 interlocking with this moves downward in FIG. Accordingly, the engaging projection 52 that is in pressure contact with the cam surface 42A of the cam member 42 retreats downward as shown in FIG. In response to the downward displacement of the engagement projection 52, the cam member 42 rotates counterclockwise in FIG. 7 by the urging force of the torsion coil spring 43 (see FIG. 7). The rotation of the cam member 42 is controlled by the third pinion gear 4 via the interlocking shaft 41.
0, the third pinion gear 40 rotates counterclockwise in FIG. 7 (clockwise in FIG. 5).

With the rotation of the third pinion gear 40,
The ring gear 19 rotates clockwise in FIG. 7 (counterclockwise in FIG. 5) about the optical axis. Ring gear 19
This rotation causes both the first pinion gear 20 and the second pinion gear 22 to rotate counterclockwise in FIG. 7 (clockwise in FIG. 5), so that the first rotation lever 21 integrated with the first pinion gear 20 is rotated. The first and second barriers 28 and 29 rotatably coupled to the free end of a second pivoting lever 23 integral with the second pinion gear 22 are displaced in opposite directions to each other, and each have a circular arc portion on the outer periphery. 28a, 29
a (see FIG. 5) stops at a position where it contacts the inner peripheral surface of the outer cylinder 16 as shown in FIG. Thereby, the lens barrier 2
8 and 29 are opened, and the state shown in FIG.

On the other hand, when the focal length selection operation member 5 moves from the OFF position to the wide angle (W) position, a wide angle code signal for keeping the photographing lens in the wide angle state is transmitted from the switch device 57 (see FIG. 7) in conjunction therewith. M is sent to a motor control circuit 59 that controls M. Therefore, the motor control circuit 59 controls the driving of the reversible motor M, and together with the base plate 10, the main optical system 3
And the reversible motor M is stopped when the main optical system 3 is displaced to the infinity position in the wide-angle state. At this time, the position of the base plate 10 at infinity in the wide angle state is determined by the rack 73 of the interlocking support 71 that moves integrally with the base plate 10.
It is determined by a distance signal transmitted from an encoder (not shown) that is interlocked with the rotation of the pinion 74 meshing with the pinion 74 (see FIG. 8).

Next, photographing in the wide-angle state is performed by pressing a release button (not shown). When the release button is pressed, first, infrared light is projected from the distance detection device 58 toward the subject, and at the same time, the reversible motor M is rotated by a signal from the motor control circuit 59. The rotation of the reversible motor M is transmitted to the drive gear 63 via a bevel gear 61 and a spur gear 62 shown in FIG. 8, whereby the drive gear 63 rotates counterclockwise and follows the lead of the feed screw shaft 64. The base plate 10 is extended to the left. At this time, the base plate 10 is guided by the guide shafts 70 and 72 and moves along the optical axis. Further, a distance detecting device 58 (see FIG. 7)
Receives the reflected light of the projection spot projected on the object, detects the position of the object, sends a detection signal to the motor control circuit 59, stops the reversible motor at that position, and adjusts the distance of the main optical system 3. Complete. Since the distance detection device 58 is generally the same as a known one, a description of its configuration will be omitted. The cam gear 66, which rotates via the reduction gear train 65, slightly rotates clockwise in FIG. 8 with the rotation of the spur gear 62 when adjusting the distance. Since the sub-lens holder 13 is engaged with the flat surface without inclination, the sub-lens holder 13 is kept immovable at the retracted position.

As described above, the movement of the main optical system 3 in the direction of the optical axis for adjusting the distance (focus adjustment) is performed by moving the base plate 10 in the optical axis direction in accordance with the rotation of the driving gear 63 provided on the base plate 10. This is done by moving to. Therefore, a helicoid screw mechanism for adjusting the distance is not provided around the main optical system 3 as in a normal photographing lens. It is formed with an extremely smaller diameter than the photographing lens barrel for a focus type camera. But,
Since the inner diameter of the outer cylinder 16 surrounding the periphery is determined by the outer diameter of the lens barriers 28 and 29 in the open state,
A relatively large donut-shaped space is created between the outer cylinder 16 and the main lens frame 6. In this space, the step motor 11, the photometric light receiving element 36, the photometric IC 95, and the like are arranged by effectively utilizing the space.

When the automatic distance adjustment in the wide-angle state is completed,
Next, the step motor 11 starts operating, and opens and closes the aperture / shutter 12. Focal length selection operation member 5 is OF
When moving from the F position to the wide angle (W) position, the photometric IC 95 and the arithmetic circuit 96 immediately start operating in FIG. 10, and a detection signal corresponding to the subject luminance is sent from the light receiving element 36 to the photometric IC 95. Then, the detection signal is converted into a digital code, and an arithmetic circuit 96 calculates an aperture value and a shutter speed value according to the subject luminance, and the result is stored in the arithmetic circuit. This stored value is
It is automatically corrected each time the luminance of the subject changes.

When the arithmetic circuit 96 receives the distance detection signal (reversible motor stop signal) from the distance detection device 58,
The aperture value and the shutter speed value based on the calculation result are pulsed and sent to the driving IC 98 at the next stage. Driving IC98
Controls the drive of the step motor 11, and in accordance with the combination of the aperture value and the shutter speed value based on the calculation result of the arithmetic circuit 96, the step motor 11 places the aperture blades 12A and 12B at the aperture openings corresponding to the aperture value. Open from the closed state,
After a delay time corresponding to the shutter speed value, the aperture blades 12A and 12B are returned to the closed state, and the exposure is completed.

Next, switching of the focal length will be described. When the focal length selection operation member 5 is moved to the telephoto (T) position as shown in FIG. 11C, a telephoto state signal is sent from the switch 4 device 57 (see FIG. 7) to the motor control circuit 59 in accordance with the movement. , The reversible motor M rotates and the base plate 1
0 is extended to the infinity position in the telephoto state beyond the close distance position in the wide-angle state. At this time, the cam gear 66
8 rotates largely in the clockwise direction in FIG. 8, and when the arm 13E of the sub lens holder 13 is pushed upward to the right in FIG. 8 against the urging force of the compression coil spring 68 on the inclined cam surface of the front cam 67. The sub-lens holder 13 rotates clockwise together with the cam gear 66, and when the photographing optical axis coincides with the optical axis of the sub-optical system 3, the sub-lens holder 13 moves leftward along the optical axis along the cam surface of the front cam 67, As shown in FIG. 2, the main optical system 3 is installed at a predetermined interval behind the main optical system 3, the main optical system 3 and the sub optical system 4 are combined, and the photographing lens is in a telephoto state having a long combined focal length.
The infinity position of the base plate 10 in the telephoto state is also determined by a distance signal from an encoder (not shown) linked to the pinion gear 74 (FIG. 8).

In the switching operation to the telephoto state,
When the focal length selection operation member 5 moves from the wide angle (W) position as shown in FIG. 11B to the telephoto (T) position shown in FIG. Since the lens barriers 28 and 29 are already in a completed state away from the surface 42A, the cam member 42 does not rotate but merely moves to the left together with the base plate 10 as shown in FIG. 11C. is there. However, the focal length selection operation member 5
Is displaced from the OFF position shown in FIG. 11A directly to the telephoto (T) position beyond the wide-angle (W) position, the cam member 42 moves to the left while rotating, so that the lens barrier 28 is rotated. , 29 are opened accordingly, and FIGS. 2 and 7
It is fully opened as shown in FIG.

In this telephoto state, the outer cylinder 16
Project from the front end of the outer case 2 as shown in FIG. However, since the outer cylinder 16 is formed in a cylindrical shape, and the gap between the outer cylinder 16 and the camera body 1 is sealed by the double light shielding member 18B, the inside of the dark box of the camera body 1 is completely light tight with a very simple structure. Maintained in state. In this case, the outer frame 13C of the sub-lens holder 13 is placed so as to coincide with the center of the optical axis as shown in FIG. 2, and there is no possibility of contact with the camera body 1, so that the wide-angle state and the housed state as shown in FIG. In this case, a part of the outer frame 13C may protrude downward from the lower edge of the base plate 10. Therefore, the size of the outer cylinder 6 is
Arc part 28 when lens barriers 28 and 29 are opened
a, 29a. Therefore, the outer peripheral radius of the outer cylinder 6 can be set small irrespective of the sub lens holder 13 located at the retracted position.

When the sub optical system 4 is inserted on the optical axis of the main optical system 3 as shown in FIG. 2 and the base plate 10 reaches the infinity position in the telephoto state, the reversible motor M stops. Thereafter, when a release button (not shown) is depressed, the distance is adjusted in the same manner as in shooting in the wide-angle state, and based on the aperture value and the shutter speed value calculated by the arithmetic circuit 96 (see FIG. 10) at the same time as the distance adjustment is completed. Step motor 11 operates,
The aperture / shutter blade 12 opens and closes, and exposure is performed.

When the focal length selection operation member 5 is switched from the telephoto (T) position to the wide angle (W) position, the reversible motor M reverses, and the base plate 10 is retracted beyond the infinity position in the telephoto state. The reversible motor stops when it reaches the wide-angle infinity position. Meanwhile, the sub lens holder 13 moves to the retracted position as shown in FIG. 1, and the main optical system 3 returns to the infinity position in the wide angle state. Then, when the focal length selection operation member 5 is moved to the OFF position, the sliding pin 55 (see FIG. 7) slides on the cam surface 50A of the cam plate 56 and is biased by the tension coil spring 53 in FIG. To move upward and engage with the upper edge 56B. As the sliding pin 55 rises, the engaging projection 52 integral with the sliding plate 50 that moves therewith moves upward. The engagement projection 52 engages with the cam surface 42A of the cam member 42 by moving upward, and rotates the cam member 42 as shown in FIG.
9 is closed. Meanwhile, the base plate 10 is slightly retracted beyond the infinity position in the wide-angle state to the lens barrel storage position and stops at that position.

When the focal length selection operation member 5 is moved directly from the telephoto (T) position to the OFF position, the base plate 1
0 returns to the lens barrel storage position. At the initial stage of the return, the engagement projection 52 is inserted on the trajectory L of the movement of the cam member 42 in the optical axis direction as shown in FIG. Shown). Therefore, the base plate 10 is recessed,
When the cam member 42 moves to the right in FIG. 11C, the cam surface 52A moves to the position indicated by the broken line (52 ').
2 and as it moves to the right, the cam surface 42
A is pushed by the engagement projection, and the cam member 42 rotates clockwise in FIG. As a result, the lens barriers 28 and 29 are automatically closed.

In the above-described embodiment, the stepper motor 11 is used as the shutter driving device for driving the aperture / shutter blade 12, but the invention is not limited to the stepper motor, but may be an ordinary small reversible motor or a magnet. .

As described above, according to the present invention, the protection members (28, 29) which can open and close the front surface of the optical system with at least two opening / closing members are provided from the frontmost surface of the lens barrel (6, 14, 16). So that the lens barrel (6, 14, 1)
6) and the lens barrel (6, 14, 16)
Is located behind the forefront of the camera cover (2) when is in the storage position, so that the barrier blade can be hidden by the lens barrel cover (14) when opened.
The appearance is beautiful and the risk of breakage is reduced. further,
The front of the lens barrel cover protrudes from the front of the lens to secure space for the barrier blades, which has a hood effect. in addition,
Since a barrier constituted by at least two opening / closing members is disposed in the lens barrel, and the barrier is positioned behind the front surface of the camera cover (2) when the lens barrel is stored, the outer diameter of the lens barrel is reduced. Can be made compact, and the thickness of the camera can be reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an embodiment of the present invention, showing a state where a main optical system is retracted to a storage position.

FIG. 2 is a cross-sectional view of the embodiment of the present invention, showing a state where the main optical system is extended to a telephoto position.

FIG. 3 is an enlarged sectional view of a sub lens holder of the embodiment of FIG.

FIG. 4 is a sectional view taken along line AA of FIG. 1;

FIG. 5 is a sectional view taken along line BB of FIG. 1;

FIG. 6 is a sectional view taken along line CC of FIG. 1;

FIG. 7 is a perspective view illustrating a configuration of the lens barrier opening / closing device illustrated in FIG. 1;

FIG. 8 is a perspective view showing an optical system moving device provided on the back surface of the base plate of FIG. 1;

FIG. 9 is a perspective view of a shutter driving unit in FIG. 1;

FIG. 10 is a block diagram of a control circuit of the aperture / shutter according to the embodiment of FIG. 1;

FIGS. 11A, 11B, and 11C are explanatory views of the operation of the lens barrier opening / closing device shown in FIG. 7 when the focal length selection operation member is at the OFF position, the wide angle position, and the telephoto position, respectively. Indicates the status.

[Description of Signs of Main Parts]

 DESCRIPTION OF SYMBOLS 1 Camera main body 2 Exterior cover 3 Main optical system 4 Sub optical system 5 Focal length selection operation member 6 Main lens frame 7 Shutter substrate 9 Barrier substrate, 10 base plate 11 Step motor (shutter driving device) 12 Aperture shutter 13 Sub lens holder 14 Front ring 16 Outer cylinder 28, 29 Lens barrier 38 Shutter control circuit board 42 Cam member 52 Engagement projection 75 Flexible printed board

Claims (2)

(57) [Claims] 1. An optical system (6), a lens barrel (6, 14, 16) that holds the optical system, is capable of moving back and forth in the direction of the optical axis, and is at least retractable to a storage position. And a camera cover (2) having an opening that can move forward and backward, and a protection member (28, 29) that can open and close the front surface of the optical system with at least two opening and closing members. , 1
The lens barrel (6, 14, 16) is disposed in the lens barrel (6, 14, 16) such that the lens barrel (6, 14, 16) is located behind the forefront of the lens (6). A camera, wherein the camera cover (2) is disposed behind the forefront of the camera cover (2). The opening has a substantially rectangular shape whose opening is shorter in the vertical direction than in the horizontal direction, and the protection member (28, 29) performs the opening and closing operation along the vertical direction. The camera according to claim 1, characterized in that: