JPH02262631A - Bifocal switching camera - Google Patents

Abstract

PURPOSE:To securely prevent a movable mirror from being stained and damaged and to enable excellent photography for a long period by switching the movable mirror to a stand-by position when the movable mirror and a finder are at wide-angle positions at the start of rewinding operation for a film. CONSTITUTION:If the movable mirror 30 is in the wide-angle state, i.e. at the 1st position when the film begins to be wound or rewound, the movable mirror is switched to the wide-angle state automatically. Consequently, the movable mirror 30 is held at a stand-by position where its reflecting surface 30a moves back away from in front of an opening 16 for exposure during the winding and rewinding operation for the film. Therefore, even if dust, dirt, etc., sticking on the film during the winding and rewinding operation for the film enter a camera main body 10 through the opening 16 for exposure, they are securely prevented from sticking on the reflecting surface 30a of the movable mirror 30. Consequently, the movable mirror is prevented from being stained and damaged to enable excellent photography for a long period.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a bifocal switching camera equipped with a telephoto shooting lens and a wide-angle shooting lens.

(Prior Art) In recent years, bifocal switching cameras have been provided in which a telephoto lens and a wide-angle lens are installed in the main body of the camera, and these lenses are used by switching between them. usually,
This type of camera has a fixed mirror located on the optical axis of a telephoto lens, an exposure aperture located on the optical axis of a wide-angle lens, and a movable mirror. and,
The photographing lens is switched by rotating the movable mirror to a telephoto position located on the optical axis of the wide-angle photographing lens or to a wide-angle position away from the optical axis of the wide-angle photographing lens.

However, in a camera with the above configuration, when the movable mirror is moved to the telephoto position, that is, when the reflective surface of the movable mirror is facing the exposure aperture, the camera body must be opened to remove or load film. When the back cover of the camera is opened, there is a risk that dust, chips, etc. may enter the camera body through the exposure opening and adhere to the reflective surface of the movable mirror. In this way, there is dust on the reflective surface of the movable mirror.
If a lump or the like adheres to the lens, it becomes impossible to take good photographs.

So, for example, in U.S. Patent Section 4.772.903,
According to the bifocal switching camera shown in 8, the movable mirror is moved to the wide-angle position in response to the opening operation of the back cover of the camera body, thereby preventing dust, flakes, etc. from adhering to the reflective surface of the movable mirror. It is configured as follows.

(Problems to be Solved by the Invention) However, the bifocal switching camera disclosed in the above US patent has the following problems.

In other words, if you wind or rewind the film while the rotary mirror is in the telephoto position, dust, flakes, etc. on the film may enter the camera body through the exposure aperture. , it adheres to the reflective surface of the movable mirror. Also, during film winding and rewinding operations,
The film slides on the film guide. Therefore, the emulsifier applied to the film peels off from the film,
The peeled emulsifier passes through the exposure opening and adheres to the reflective surface of the movable mirror. Therefore, it becomes difficult to take good pictures.

Furthermore, the leading end of the film is usually curled inward. . Therefore, when the leading edge of the film passes over the exposure opening at the end of the rewinding operation, the leading edge of the film may protrude into the camera body through the exposure opening. Therefore, when the movable mirror is at the telephoto position, there is a risk that the reflective surface of the movable mirror may be damaged by the leading end of the film protruding into the camera body. If the reflective surface of the movable mirror is scratched, it will be difficult to take good pictures.

The present invention has been made in view of the above points, and its purpose is to provide a bifocal switching camera that can reliably prevent dirt and damage to the movable mirror and that can take good pictures over a long period of time. There is a particular thing.

['Bright Configuration] (Means and Effects for Solving the Problem) In order to achieve the above object, according to the bifocal switching camera of the present invention,
If the movable mirror and finder are in the first position at the start of the film winding operation, the movable mirror is switched to the second position, and after the film winding is finished, the movable mirror is switched to the first position to rewind the film. When the movable mirror and the finder are in the first position at the start of operation, a switching means is provided for switching at least the movable mirror to the second position.

According to the above configuration, during film winding and rewinding operations, the movable mirror is held in the second position, that is, in a state in which its reflective surface is retracted from the front of the exposure aperture. Therefore, dirt and damage to the reflective surface of the movable mirror during film winding and rewinding operations are prevented.

(Embodiments) Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

1 to 12 show a bifocal switching camera according to a first embodiment of the invention. 1st r! ! As shown in J, this camera includes a camera body 10 having a back M12 that can be opened and closed. By opening the back cover 12, film can be loaded into and removed from the camera body 10. Camera body 10
When loaded into the camera body, the film 14 is positioned so as to cover one end side of an exposure opening 16 formed in the camera body.

Inside the camera body 10, there is a first photographing optical system 18 that has a relatively long focal length and is used for telephoto photography, and a second photographic optical system that has a relatively short focal length and is used for wide-angle photography. 20 are provided. The second photographing optical system 20 is arranged so that its front axis passes through the center of the exposure aperture 16 and is perpendicular to the film 14 . Further, the first photographing optical system 18 is provided above the second photographing optical system 20 so that its optical axes are parallel to each other. and,
These photographic optical systems 18 and 20 are supported by a support frame 22 so as to be movable along the optical axis direction. 1st
Transparent glass windows 24, 25 are provided in front of the second photographing optical system 18, 20, respectively. Also,
Inside the first photographing optical system 18 and the second photographing optical system 18
A shutter 21 is provided behind the.

Behind the first photographing optical system 18 in the camera body 10,
A fixed mirror 26 is provided and is positioned obliquely on the optical axis of the first photographing optical system. Furthermore, a movable mirror 30 fixed on a support plate 28 is disposed within the camera body 10. One end of the support plate 28 is rotatably attached to the camera body 10. Thereby, the movable mirror 30 is rotatable together with the support plate 28 between a first position shown by a solid line in FIG. 1 and a second position shown by a two-dot chain line.

In the first position, the movable mirror 30 is positioned obliquely on the optical axis of the second photographing optical system 20, and its reflective surface 30a faces the exposure aperture 16 and the fixed mirror 26. Therefore, the movable mirror 30 guides the optical image that enters the camera body 10 through the first photographing optical system 18 and is reflected by the fixed mirror 26 onto the film 14 through the exposure aperture 16.

As a result, telephoto photography using the '1st photographing optical system 18 becomes possible. In the second position, the movable mirror 30 is moved away from above the optical axis of the second photographing optical system 2o, and its reflective surface 30a is moved away from in front of the exposure aperture 16, and the optical image reflected by the fixed mirror 26 is removed. block the optical path of Therefore, instead of the optical image that entered through the first imaging optical system 18, the optical image that entered through the second imaging optical system 20 is introduced onto the film 14 through the exposure aperture 16. As a result, wide-angle photography using the second photography optical system becomes possible.

In this way, by switching the movable mirror 30 to the first or second position, telephoto shooting and wide-angle shooting can be selectively performed.

Further, the bifocal switching camera includes a known finder (not shown) disposed within the camera body. This finder is provided so as to be movable between a first position suitable for telephoto shooting and a second position suitable for wide-angle shooting.

The finder and movable mirror 30 are switched in conjunction with each other or independently by a switching mechanism 32, which will be described later.

As shown in FIGS. 2 to 4, the switching mechanism 32 is
It includes a switching motor 34 and a drive gear 38 that is rotationally driven by the switching motor via a gear train 36. A first cam 40 for switching the movable mirror 30 is fixed on the drive gear 38 and rotates integrally with the drive gear. Further, a second cam 42 for switching the finder is provided on the first cam 40.

The first cam 40 is formed by cutting out a part of a disc, and the outer peripheral surface of the first cam 40 forms a cam surface 44 . The cam surface 44 is composed of a pair of plane parts 44a that are parallel to each other and a pair of arcuate parts 44b that are positioned between these plane parts to face each other.

The second cam 42 has a pivot shaft 4 protruding from the first cam 40.
A disc-shaped main body 46 rotatably supported around 1;
It has a pair of suppressing protrusions 48 erected on the outer periphery of the main body. These suppressing protrusions 48 extend parallel to the pivot shaft 41 and are provided 180 degrees apart from each other around the pivot axis.A pair of guide holes 50 are formed in the main body 46.A pair of guide holes 50 are formed between the suppressing protrusions 48. are located opposite each other. These guide holes 5o are formed in an arc shape centered on the pivot 41, and the center angle of each guide hole is set to 90 degrees. A guide pin 52 protruding from the first cam 40 is inserted into the - side guide hole 50 . The guide bin 52 has a guide hole 50
The first and second cams 40,42 are movable relative to each other by a maximum of 90 degrees about the pivot 41.

Furthermore, four V-shaped notches 54 are formed on the outer circumferential surface of the main body 46 of the second cam 42 and are spaced apart from each other by 90 degrees. Two of the notches 54 are formed around the pivot 41 at the same position as the suppressing projections 54 . The second cam 42 is elastically positioned by positioning means.

In other words, the positioning means includes a compression spring 56 attached to the camera body 10 and a ball 58 fixed to one end of the compression spring and biased toward the outer peripheral surface of the second cam 42.
It has Then, the ball 58 is inserted into one notch 54.
By engaging with the second cam 42, rotation of the second cam 42 is elastically restricted.

The switching mechanism 32 includes a mirror switching arm 60 connected to the movable mirror 30 and a finder switching arm 62 connected to the finder. One end of the mirror switching arm 60 is urged by a compression spring 64 attached to the camera body 10 and comes into contact with the cam surface 44 of the first cam 40 . In addition, the finder switching arm 5
2 is a tension spring 6 attached to the camera body 10;
6 and comes into contact with the pressing protrusion 48 of the second cam 42.

A normally closed detection switch 68 for detecting the position of the movable mirror 30 is provided near the first cam 40. This detection switch 68 has a negative pair of terminals 68m, 68
b, and the terminal 68a is located on the movement path of the mirror switching arm 60.

Therefore, as will be described later, when the movable mirror 30 is switched to the first position, the detection switch 68 is switched OFF by the mirror switching arm 60.

FIG. 4 shows a state in which the movable mirror 30 and the finder are each set at the first position, that is, the telephoto state (T-shape!). In this state, the mirror switching arm 60 Arc portion 44 of cam surface 44 of 40
b and is pushed up to the telephoto position shown. The terminal 68a of the detection switch 68 is pressed by the mirror switching arm 60 and separated from the other terminal 68b. As a result, the detection switch 68 is turned off. Further, the second cam 42 is held by positioning means such that the pair of pressing protrusions 48 are aligned in a direction parallel to the linear portion 44a of the first cam 40. The finder switching arm 62 is pushed up to the telephoto position shown in the figure by one of the suppressing protrusions 48.

Further, in the state shown in FIG. 4, the guide bin 52 of the first cam 40 is located at the lower end of the guide hole 50 formed in the second cam 42, that is, on the downstream side in the counterclockwise direction about the pivot shaft 41. It is located at the edge of the.

From the state shown in FIG. 4, the drive gear 38 and the first cam 40
When is rotated 90 degrees forward by the switching motor 34, that is, when it is rotated 90 degrees counterclockwise around the pivot shaft 41,
As shown in FIG. 5, one straight portion 44a of the cam surface 44
faces the mirror switching arm 60. Thereby, the mirror switching arm 60 is moved to the straight portion 4 by the compression spring 64.
4a, and at the same time switches the movable mirror 30 from the first position to the second position. Therefore, the movable mirror 30 is in a wide-angle state (W state). Further, the mirror switching arm 60 is connected to the detection switch 6
As a result, the detection switch is turned ON.

On the other hand, as the first cam 40 rotates, the second cam 42 is pressed by the guide pin 52 located at the counterclockwise downstream end of the guide hole 50 and rotates 90 degrees counterclockwise. Thereby, the second cam 42 is connected to the pair of suppressing protrusions 4.
8 are moved to be lined up in a direction substantially parallel to the finder switching arm 62, and are held by the positioning means. The finder switching arm 62 is connected to a tension spring 66.
Since it is urged toward the pressing projection 48 by the pressing projection 48, it follows the movement of the pressing projection and descends to the wide-angle position shown in the figure. At this time, the finder switching arm 62 switches the finder from the first position to the second position. Therefore, the finder is in a wide-angle state (W-shaped 9).

When the first cam 40 is rotated 90 degrees forward by the switching motor 34 from the state shown in FIG. 5, the second cam 42 is also rotated 90 degrees forward in the same way as described above, and the state shown in FIG. Set. Thereby, the movable mirror 30 and the finder are switched from the wide-angle state to the telephoto state.

In this manner, by rotating the drive gear 38 in the forward direction by the switching motor 34, the movable mirror 30 and the finder can be switched to the telephoto state or the wide-angle state in conjunction with each other.

Further, when the driving gear 34 and the first cam 40 are reversed 90 degrees by the switching motor 34 from the telephoto state shown in FIG. 4, that is, when they are rotated 90 degrees clockwise around the pivot shaft 41, As shown in FIG. 6, the straight portion 44a of the cam surface 44 faces the mirror switching arm 60. As shown in FIG. Therefore,
The mirror switching arm 60 moves from the telephoto position to the wide-angle position and switches the movable mirror 30 to the wide-angle state. At the same time, the mirror switching arm 60 turns on the detection switch 68. At this time, the guide pin 52 of the first cam 40 also rotates 90 degrees clockwise, but it only moves within the guide hole 50 from one end to the other and does not press the second cam 42. Therefore, the second cam 42 does not rotate.
It is maintained in the same state as in FIG. Therefore, only the movable mirror 30 is switched from the telephoto state to the wide-angle state, and the finder is maintained in the telephoto state.

Similarly, from the state shown in FIG.
When rotated forward, only the movable mirror 30 is switched from the wide-angle state to the telephoto state, returning to the state shown in FIG. 4.

FIG. 7 shows the entire structure of the bifocal switching camera in blocks. Bifocal switching camera uses film 14
It has a film transport mechanism 70 that transports the film for rewinding and winding. The transport motor drive circuit 72 drives the transport motor 76 of the film transport mechanism 7o based on control signals from the CPU 74, that is, winding signals and rewinding signals. Further, the encoder circuit 78 generates a transport pulse corresponding to the film transport amount and inputs it to the CPU 74. The switching motor drive circuit 80 is
The switching motor 34 of the switching mechanism 32 is driven in response to a switching signal from the CPU 74.

Further, when the detection switch 68 is closed, the port PT/w of the CPU 74 becomes low level (L). Further, when the intermediate rewind switch 82 provided on the outer surface of the camera body 10 is closed, the boat PR of the CPU 74 becomes low level.

Next, the operation of the bifocal camera configured as above will be explained.

Normal switching between the movable mirror 30 and the finder is performed by pressing a switch (not shown) provided on the outer surface of the camera body 10. When the changeover switch is pressed, the CPU 74 detects the positions of the movable mirror 30 and the fender based on the detection signal from the detection switch 68, and also detects the positions of the changeover motor drive circuit 80.
Outputs a mode switching signal to. In response to this, the switching motor 76 of the switching mechanism 32 is rotated in the forward direction, and the movable mirror 3
0 and the viewfinder switches from telephoto to wide-angle or vice versa. Subsequently, the CPU 74 detects the positions of the movable mirror 30 and the finder again based on the detection signal from the detection switch 68, thereby completing the switching operation.

FIG. 8 shows the flow of the switching operation described above.

Winding of the film is performed as follows.

FIG. 9 and FIG. 10 respectively show an operation flow and a flowchart at the time of winding.

When a film winding signal is input to the CPU 74, the CPU 74
U detects the positions of the rotating mirror 30 and the finder based on the detection signal from the detection switch 68. When the movable mirror 30 is in the telephoto state located at the first position, that is, when the boat is not pr7w-L, C
The PU 74 reverses the switching motor 34 of the switching mechanism 32. Therefore, as shown in FIG. 6, only the first cam 40 is reversed by 90 degrees, the movable mirror 30 is switched from the telephoto state to the wide-angle state, and the finder is maintained in the telephoto state. Subsequently, the CPU 74 detects the position of the movable mirror 30 again based on the detection signal from the detection switch 68, and after confirming that the movable mirror is in the wide-angle state (boat PT/W-L), switches the film transport mechanism 70 is driven to wind the film 14 one frame. After the winding operation is completed, C
By rotating the switching motor 34 in the forward direction, the PU74
The first cam 40 is rotated 90 degrees forward. Therefore, the movable mirror 30 is switched from the wide-angle state to the telephoto state, and as a result, the state before film winding is set as shown in FIG. After switching of the movable mirror 30 is confirmed at Ts by a detection signal from the detection switch 68, the winding operation is completed.

On the other hand, if the movable mirror 30 and finder are in the wide-angle state when the film winding signal is input to the CPU 74, the film 1 is immediately
4 winding operation is started.

Rewinding of the film 14 is performed as follows.

FIG. 11 and FIG. 12 respectively show an operation flow and a flowchart at the time of rewinding.

When the end of the film is detected by a known film end detection means, or when the midway rewind switch 82 is pressed and the midway rewind Cg number is input, the CPU 7
4 detects the positions of the movable mirror 30 and the fine lens based on the detection signal from the detection switch 68. When the movable mirror 30 and the finder are in the telephoto state, that is, when the boat is not PT/W-L, the switching mechanism 34
The first and second cams 40 and 42 are rotated 90 degrees in the normal direction, and the movable mirror and finder are switched to the wide-angle state.

Therefore, the movable mirror 30 is switched from the first position to the second position. Thereafter, the CPU 74 again detects the positions of the movable mirror 30 and the finder based on the detection signal from the detection switch 68, and after confirming that they are in the wide-angle state, that is, on the boat PT/ν, the film transport mechanism 74 is driven to start rewinding the film 14.

When the end of the film 14 is detected or when a midway rewind signal is input, if the movable mirror 30 and finder are in the wide-angle state, the film 14 is immediately rewinded without switching them. Return begins.

For example, when opening the back cover 2 of the camera body 1o in order to take out or replace the film 1/1, the movable mirror 30 and the viewfinder are moved by a known holding means in conjunction with the opening of the cover. The image is kept in a wide-angle state.

According to the bifocal switching camera configured as above,
If the movable mirror 30 is in the wide-angle state when starting a film winding or rewinding operation, that is, if the movable mirror is in the first position, the movable mirror is automatically switched to the wide-angle state. Therefore, during film winding and rewinding operations, the movable mirror 30 is held at the second position where its reflective surface 30a is retracted from in front of the exposure opening 16. Therefore, during the winding and rewinding operations, dust and flakes attached to the film, or emulsifiers peeled off from the film enter the camera body through the exposure opening 16 (and even if these It is possible to reliably prevent the particles from adhering to the reflective surface 30a of 30.

Further, even if the leading end of the film protrudes into the camera body 10 through the exposure opening 16 at the end of rewinding the film, the leading end of the film will not come into contact with the reflective surface 30a of the 1-41 moving mirror 30. As a result, damage to the movable mirror can be reliably prevented. Therefore, according to the bifocal switching camera of this embodiment, it is possible to take good pictures over a long period of time.

Further, according to this embodiment, when the movable mirror 30 and the finder are in the telephoto state when winding the film 14, only the movable mirror 30 is switched to the wide-angle state,
The viewfinder remains in telephoto mode. Therefore, even when the operator winds the film while observing the subject through the finder, the field of view of the finder does not change during the winding operation, and the operator does not feel uncomfortable. Moreover, since the movable mirror 30 is immediately returned to the telephoto state after winding of the film 14 is completed, telephoto photography can be continued.

Note that this invention is not limited to the embodiments described above, and can be modified in various ways within the scope of this invention.

For example, in the above embodiment, when rewinding the film with the movable mirror and finder in the telephoto state, only the movable mirror may be switched to the wide-angle state, and after rewinding, the film may be returned to the telephoto state. Further, although the switching mechanism is configured to switch between the movable mirror and the finder using a single motor, the movable mirror and the finder may be switched using separate motors. And the driving source is not limited to the motor.
Solenoids, voltage actuators, etc. may also be used.

[Effects of the Invention] As described above, according to the present invention, the movable mirror is moved to the second position in conjunction with the film winding and rewinding start operations, that is, the position where the reflective surface is retracted from the front of the exposure aperture. Since it is provided with a switching means for switching to , it is possible to provide a bifocal switching camera that prevents dirt and damage to the movable mirror and can perform good photography over a long period of time.

[Brief explanation of drawings]

FIGS. 1 to 12 show two diagrams according to an embodiment of the present invention.
1 is a sectional view of the camera, FIG. 2 is a perspective view showing the switching mechanism, FIG. 3 is an enlarged perspective view of the first and second cams, and FIGS. FIG. 6 is a plan view showing the different operating states of the switching mechanism, FIG. 7 is a block diagram schematically showing the overall structure of the camera, and FIG. 8 is for explaining the switching operation of the movable mirror and finder. The operation flow of FIGS. 9 and 10 explains the film winding operation. FIGS. 11 and 12 are an operation flow and flowchart for explaining the film rewinding operation. DESCRIPTION OF SYMBOLS 10... Camera body, 12... Back cover, 14... Film, 16... Exposure aperture, 18... First photographing optical system, 20... Second photographing optical system, 26... Fixed mirror 30... Movable mirror 30a... Reflective surface, 3
2... switching mechanism, 34... switching motor, 40...
. . . first cam, 42 . . . second cam, 70 . . . film transport mechanism. Figure 10: Patent Attorney Patent Attorney Jun Tsuboi Patent Application No. 1-84441 Title of the invention Relationship to the bifocal switching camera correction case Patent applicant

Claims (1)

[Scope of Claims] A first photographing optical system; a second photographing optical system that is installed alongside the first photographing optical system and has a focal length different from that of the first photographing optical system; a fixed mirror provided on the optical axis of the second photographing optical system; an exposure aperture located on the optical axis of the second photographic optical system; a reflective surface located opposite the exposure aperture; a first position for guiding an optical image reflected by the fixed mirror through the first photographing optical system to the exposure aperture; and a second position for guiding the optical image reflected by the fixed mirror through the first photographing optical system to the exposure aperture; a second position where the optical image passing through the system enters the exposure aperture; a movable mirror provided so as to be switchable; a first position adapted to the first photographing optical system; a finder which is provided so as to be switchable between the first position and the second position adapted to the photographing optical system; If the movable mirror and finder are in the first position when the film winding operation starts, the movable mirror is switched to the second position, and after the film winding is finished, the movable mirror is switched to the first position, and the film winding operation is started. A bifocal switching camera comprising: switching means for switching at least the movable mirror to the second position when the movable mirror and the finder are in the first position at the start of the return operation.