JP2000147598A - Synchro signal generating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To generate a synchro signal at exact timing by detecting the actual opening/closing of a shutter blade. SOLUTION: A photointerrupter is arranged so that the shutter blade is inserted and pulled out between a light projector and a light receiver when the shutter blade performs opening/closing operation, and it detects that the shutter blade is moved to a position where a shutter aperture is nearly totally opened. An EEPROM is incorporated together with a shutter device in a lens unit. A delay time Td expressing deviation between timing that a detection signal from the photointerrupter is outputted and timing that the shutter aperture is actually totally opened is measured and written in the EEPROM at the time of production. At the time of photographing, the synchro signal is generated when the delay time Td elapses after the detection signal is generated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sync signal generator for generating sync signals for flash photography.

[0002]

2. Description of the Related Art When the luminance of a subject is low, photography is performed using an artificial light source. There are various types of artificial light sources, but at present, strobe devices having good responsiveness and short light emission time are widely used. In order to perform flash photography using a flash device built in the camera or an external flash device, the synchronization timing differs depending on the type of the shutter device and the like, but the opening and closing operation of the shutter device and the flash emission are performed in synchronization. There is a need. When a lens shutter is used as the shutter device, in order to effectively use the strobe light, when the shutter opening of the shutter device is fully opened, the sync signal is generated by the sync signal generator to emit the strobe light. Like that.

The synchronizing signal generator is provided with a mechanical device that operates when the shutter blades fully open the shutter opening due to the operation or position change of members for driving the shutter blades, members driven in conjunction with the shutter blades, and the like. By turning on the sync switch, a sync signal is generated.

[0004]

As described above, the synchro signal generator does not detect the opening / closing operation of the shutter blade itself, but turns on the synchro switch by a member or the like driven in conjunction with the shutter blade. By doing so, a synchro signal is generated. For this reason, many parts such as a synchro switch, a member for turning on the switch, and a member interlocked with the shutter blade are required, which hinders miniaturization. There has been a problem that a synchro signal may be generated at a timing different from the fully opened timing.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide a synchro signal generator which is advantageous for miniaturization and can generate a synchro signal at accurate timing.

[0006]

In order to solve the above problems, according to the first aspect of the present invention, a light emitter and a light receiver arranged so as to sandwich a moving path of a shutter blade which is fully closed after reaching a fully open position are provided. A photo-interrupter, which photoelectrically detects that a part of the shutter blade has moved between the light emitter and the light receiver in the process of moving the shutter blade in the opening direction, and outputs a detection signal; A sync signal generating means for generating a sync signal in response to a detection signal from the interrupter.

According to the second aspect of the present invention, the photo interrupter is arranged at a position for outputting a detection signal before the shutter blade reaches the fully opened position, and the synchronizing signal generating means is provided in accordance with the individual difference of the shutter device. And a delay time adjusting means for generating the synchronization signal after a lapse of the delay time by the adjusting means from the time when the detection signal is received.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 2 showing the appearance of a camera embodying the present invention, and FIG.
The camera 2 includes a camera body 3, a film holder 4 attached to the rear side of the camera body 3, and a camera body 3.
This is a system camera constituted by a combination of various mounting units such as a lens unit (photographing lens) 5 mounted on the front side of the camera and a waist level finder 6 mounted on the upper part of the camera body 3.

The camera main body 3 comprises a box-shaped main body 8 in which a mirror mechanism, a control circuit and the like are incorporated, and a focus adjusting mechanism 9 provided below the main body 8. Openings 10 and 11 are provided on the front side and the back side of the main body 8, respectively.
Are formed. A bellows 13 for blocking the photographing optical path is attached between the front opening 10 and the lens board 12 constituting the focus adjustment mechanism 9. The film holder 4 is attached to the opening 11 formed on the back side of the main body 8 so as to face the opening.

A lens unit 5 is mounted on the front surface of the lens board 12, and is locked by a lock lever 15 provided on the upper part of the lens board 12. The lens unit 5 is provided with various focal lengths, and these can be exchanged and used as needed. The lens unit 5 includes a photographing optical system (lens) 16
, Aperture device 17, shutter device 18, EEPROM
M19 (see FIG. 7).

The aperture device 17 includes an aperture blade 17a and an actuator 17b for driving the aperture blade 17a. An aperture value is set by operating an aperture lever 17c provided on the outer periphery of the lens unit 5. The aperture device 17 has an open aperture formed by the aperture blades 17a during non-photographing, and is stopped down during photography so as to form an aperture having a set aperture value.

The shutter device 18 includes a shutter blade 18a.
, Actuator 18b, and photo interrupter 20
And a lens shutter incorporated in the lens unit 5. The actuator 18b is
The shutter blade 18a is opened and closed at a shutter speed set by the main body 8 according to a control signal from the main body 8. The shutter blade 18a is composed of, for example, a plurality of shutter blades 18a.
By being swung by 8b, it is swung between a fully open position where the shutter opening is fully opened and a shielding position where the shutter opening is closed.

At the time of non-shooting, the shutter blade 18a is in the fully open position, and the subject light having passed through the shooting optical system 16 passes through the lens board 12, the bellows 13, and the opening 10 and enters the main body 8. Further, at the time of photographing, the shutter blade 18a is once swung to the shielding position, is set to the fully open position, and is returned to the closed position again after a shutter time corresponding to the set shutter speed. Thereby, one photographing is performed. After shooting, shutter blade 1
8a is again set to the fully open position.

In this example, the shutter device is a behind-the-lens shutter disposed behind the photographing optical system 16, but it may be a between-the-lens shutter or a before-the-lens shutter.

The photo interrupter 20 detects that the shutter blade 18a has been opened to the fully open position during photographing.
Is used to control whether or not is opened to the fully open position and to generate a sync signal for strobe tuning. EEPROM
In 19, the number of operations of the shutter device 18 is written. Further, the EEPROM 19 has a function as an adjusting means for adjusting the generation timing of the synchro signal, and the delay time Td unique to the lens unit 5 is provided.
Is written at the time of manufacture.

The sync signal is to be generated at the moment when the shutter blade 18a reaches the fully open position, and may be generated at the moment when the shutter blade 18a reaches the fully open position by the photo interrupter 20. But actually,
Due to an error caused by the mounting accuracy of the photo interrupter 20 to the shutter device 18, the photo interrupter 20
A slight shift occurs between the timing of detecting the shutter blade 18a by the above and the timing of actually reaching the fully opened position of the shutter blade 18a. Therefore, the EEPROM 1
The synchronization timing is corrected by using the delay time Td written in 9 so that the synchronization signal is generated when the shutter blade 18a actually reaches the fully open position.

On the rear side of the lens unit 5 and on the front side of the lens board 12, there are provided contact points 21 for electrically connecting the components of the lens unit 5 to a control circuit and a power supply circuit incorporated in the camera body 3. 22 are provided. The lens board 12 and the camera body 3 are electrically connected by a flexible cord 23.

In the main body 8, an opening 11 on the back of the main body 8 is provided.
A light-shielding plate 25 that closes the opening 11 in a light-tight manner and a mirror 26 that changes the optical path of subject light are arranged in front of. As shown in FIG. 3, the light-shielding plate 25 and the mirror 26 are arranged so that the light-shielding plate 25 closes the opening 11 and the mirror 26 transmits the subject light from the lens unit 5 to the main body around the shaft attachment portion 27 as shown in FIG. 8 is rotatable between a DOWN position where the light is reflected upward and an UP position where the opening 11 is opened by rotating clockwise in FIG. At the time of non-photographing, the light shielding plate 25 and the mirror 26 are at the DOWN position to shield the inside of the film holder 4, and at the time of photographing, are rotated to the UP position to allow the subject light to pass through the opening 11.

A focusing glass 28 is fitted on the upper surface of the main body 8, and the subject light reflected by the mirror 26 at the UP position is focused on the focusing glass 28. As shown, a focus glass 28 is provided on the upper surface of the main body 8.
A foldable waist level finder 6 that makes it easy to see from above, an AE finder (not shown) having an automatic exposure function, and the like are mounted according to shooting conditions and applications.

The AE finder is a focus glass 2
A viewfinder optical system equivalent to an angle finder that bends the subject light imaged on 8 so that it can be viewed as an erect image, and a light receiving element that measures the brightness of the subject light imaged on the focus glass 28 An AE finder control circuit for driving the light receiving element, determining a shutter time based on a photometric value of the light receiving element and an aperture value set by the lens unit 5, and inputting the shutter time to a control circuit of the camera body 3. And so on. Although not shown, contact points for electrically connecting an AE finder control circuit to a control circuit and a power supply circuit in the camera body 3 are provided on a lower portion of the AE finder and an upper surface of the main body 8, respectively.

On one side of the main body 8, a shutter speed adjusting dial 33 for switching between a shutter speed and an AE mode, and a film winding device serving as a main power switch for turning on and off the power of the camera 2 are provided. An operation panel 37 provided with a mode switching dial 34 for performing mode switching, a mirror up switch 35 for forcibly turning the light shielding plate 25 and the mirror 26 in the main body unit 8 to the UP position, a release switch 36 and the like are provided. I have.

Further, a synchro contact 38a is provided on the operation panel 37. This synchro contact 3
An external strobe device is connected to 8a. The synchro contact 38a is connected to the synchro switch 38 inside the main body 8.
(See FIG. 7), and the strobe device connected by turning on the synchro switch 38 emits strobe light. That is, ON of the synchro switch 38 is a synchro signal for strobe tuning, and strobe light emission is performed when the shutter opening is fully opened.

On the upper surface of the main body 8 and beside the focus glass 28, the state of the camera, such as whether or not photographing is possible, the remaining battery power,
A liquid crystal display (LCD) 39 for displaying a warning such as abnormal exposure or an error is provided.

The focus adjustment mechanism 9 includes a base 40 attached to the lower surface of the main body 8 and a pair of focusing rails 4 protruding forward from the base 40.
1 and a slide portion 42 which is movable along the focusing rail 41 and has the above-mentioned lens board 12 mounted on the upper portion thereof. An operation knob 43 is rotatably attached to the side of the slide portion 42. When the operation knob 43 is rotated, the slide portion 42 moves along the focusing rail 41 and the camera body 3
Focus adjustment is performed by changing the distance between the lens unit 5 and the lens unit 5.

The lens board 12 is mounted on a frame part 45 mounted on the upper part of the slide part 42. The frame part 45 is slidable and rotatable in a left-right direction orthogonal to the sliding direction of the slide part 42. The lens board 12 is attached to the frame 45 so as to be rotatable in a vertical direction perpendicular to the direction of rotation of the frame 45. Thus, the camera 2 can perform tilt shooting without using any special device.

In the film holder 4, a film loading chamber 48 in which a brownie-sized photographic film 46 is loaded.
And an aperture 49 for defining an exposure range for the photographic film 46. Masks of various sizes are attached to the aperture 49, and the photographing size can be appropriately changed. Aperture 4
A light-shielding lid 50 is inserted in front of 9 to light-tightly shield the inside of the film holder 4 when removing the film holder 4 from the camera body 3. The light shielding cover 50 is pulled out of the film holder 4 at the time of photographing.

Further, the film holder 4 is attached to the camera body 3.
By rotating the film holder 4 by 90 ° without changing the attitude of the camera 2, the vertical and horizontal directions of the shooting screen can be switched. The display range of the focus glass 28 is also switched between vertical and horizontal in conjunction with the rotation of the film holder 4.

Further, the first frame of the photographic film 46 is set in the aperture 49 in the film holder 4, and the photographic film 46 is wound up by one frame for each photographing. Film 4
A hoisting mechanism 51 for winding all the rolls 6 is incorporated. Also, a contact portion is provided between the rear side of the camera body 3 and the front side of the film holder 4 so that the control circuit and the power supply circuit in the film holder 4 can be electrically connected to the control circuit and the power supply circuit in the camera body 3. 52 and 53 are provided respectively. The contact portions 53 of the film holder 4 are provided at two places so that they can be connected to the contact portions 54 of the camera body 3 even when the film holder 4 is rotated by 90 °.

On the upper surface of the film holder 4, a liquid crystal display 55 for displaying various information of the loaded photographic film 46 and information of the camera 2 itself, and the liquid crystal display 55 displays the total number of shots of each unit. A total shot button 56 and the like are provided.

The liquid crystal panel 55 has a mask size (for example, 6 cm × 8 cm) representing the size of the mask attached to the aperture 49 of the film holder 4, and the type (120 type or 220 type) of the loaded photo film 46. Type, photographic film 46
, The number of shots indicating the number of shots, a camera monitor indicating the state of the camera 2, the total number of shots, and the like. If the photo interrupter 20 does not detect that the shutter blade 18a has not been swung to the fully open position during photographing, it warns that the shutter blade 18 has not been opened and closed normally.
The mark corresponding to the lens unit 5 of the camera monitor is displayed blinking.

In FIG. 4 showing a schematic configuration of the shutter device 18, two shutter blades 18 a are rotatably supported by a shaft 60. Each shutter blade 18a
A pin 62a protruding from one end of a connecting member 62 is engaged with the long hole 61 formed in the first hole. The connecting member 62 is slidable vertically in the drawing. Opening / closing mechanism 18
As is well known, the solenoid 63, which is a part of b, comprises a bobbin 63a, a coil 63b wound around the outer periphery of the bobbin 63a, and a plunger 63c slidable along the axial direction of the bobbin 63a. . The other end of the connecting member 62 is connected to the plunger 63 a and is urged downward by a spring 64. The lock mechanism 65 locks the connecting member 62 so as to hold the shutter blade 18a at the fully opened position where the shutter opening 66 is fully opened at the time of non-photographing, and releases the lock at the time of photographing. The solenoid 63 and the lock mechanism 65 are controlled by the main body 8.

When a drive current is supplied to the coil 63b, the plunger 63a is pressed against the bias of the spring 64 as shown in FIG.
At the same time, the connecting member 62 is slid upward, and the shutter blade 18a swings to the fully opened position where the shutter opening 66 is fully opened. At the time of non-shooting, the lock mechanism 65 remains in this state.
The connecting member 62 is locked by the
Is maintained in a fully opened state. Further, at the time of photographing, the drive current is continuously supplied to the solenoid 63, so that this state is maintained for a time corresponding to the shutter speed.

The shutter opening 6 immediately before and at the time of photographing.
6 is closed by stopping the drive current flowing through the coil 63c in a state where the lock by the lock mechanism 65 is released. When the driving current is stopped, as shown in FIG.
3a, the shutter blades 18a are slid downward in the closing direction.
Is swung to the closed position.

During photographing, the shutter blade 18a is swung from the blocking position to the fully open position as described above, and is held at the fully open position for a time corresponding to the shutter speed, and then returns to the closed position once. Open / close operation is performed. At any shutter speed, the shutter blades 18a
Swinged to fully open position.

As shown in FIG. 4, the photo interrupter 20 comprises a light projecting device 20a for outputting detection light and a light receiving device 20b for receiving detection light.
0b outputs a photoelectric signal based on the light reception result. For example, the light emitting device 20a uses a light emitting diode, and the light receiving device 20b uses a phototransistor. The photo interrupter 20 is arranged so that the light emitter 20a and the light receiver 20b face each other with a moving path on which one of the shutter blades 18a swings, and the shutter blade 18a is inserted between the light emitter 20a and the light receiver 20b. It has been made to escape.

FIG. 5 shows a case where the shutter blade 18a is in the blocking position, and when the shutter blade 18a does not enter the space between the light emitter 20a and the light receiver 20b (the position indicated by reference numeral 67 in FIG. 5), Since the detection light from 20a is received by the light receiver 20b, an "H level" photoelectric signal is output. On the other hand, as shown in FIG. 6, when a part of the shutter blade 18a reaches between the light projector 20a and the light receiver 20b, the detection light from the light projector 20a is blocked by the shutter blade 18a, and the detection light is Since light is no longer received at 20b, the light receiver 20b changes the photoelectric signal from “H level” to “L level”. Photo interrupter 20
Sends the change of the photoelectric signal from “H level” to “L level” as a detection signal to the control circuit of the main body 8.

The photo interrupter 20 is arranged to output a detection signal when the shutter blade 18a reaches the fully open position. Then, based on this detection signal, it is determined whether or not the shutter blade 18a has been swung to the fully open position, and the opening and closing operation of the shutter blade 18a is monitored and a synchro signal is generated.

By the way, the photo interrupter 20 may be displaced due to an assembling error or the like between the timing at which the detection signal is output and the timing at which the shutter blade 18a actually reaches the fully open position. Therefore,
In this camera, a detection signal is output when the shutter blade 18a actually reaches a range from the fully open position to a position slightly short of this fully open position in consideration of an assembling error of the photo interrupter 20, and the like. The timing deviation is stored in the EEPROM 19 of the lens unit 5 as the delay time Td measured at the time of manufacturing. Then, the sync signal is generated at a timing delayed by the delay time Td from the timing at which the detection signal is generated. Thus, the strobe light is emitted more accurately at the timing when the shutter blade 18a reaches the fully opened position.

The delay time Td is determined based on the timing at which the shutter blade 18a is opened and closed with respect to the completed lens unit 5 incorporating the shutter device 18 and the like. It is determined for each lens unit 5 by examining the difference from the reached timing.

FIG. 7 is a block diagram showing a circuit configuration of the camera 2. The camera panel 3 includes the operation panel 3 described above.
7, a synchro switch 38, a synchro contact 38a, a liquid crystal display 39, a mirror mechanism 71, a mirror drive circuit 72, an EEPROM 73, an exposure monitor circuit 74,
A drive circuit 75, a timer 76 and the like are provided.

The camera main body 3 incorporates a main body MPU 80 which is a control circuit for controlling the above circuits and the circuits provided in the lens unit 5 and the AE finder. The main body MPU 80 has a CPU and an RO in which programs for performing various sequences are written.
M, a RAM used as a work memory, a communication circuit for communicating with the film folder 4, and the like.

The mirror mechanism 71 includes a light shielding plate 25, a mirror 2
6, a detection circuit for detecting these operations. The mirror driving circuit 72 drives the motor 72a to drive the light shielding plate 25.
And the mirror 26 swings between the UP position and the DOWN position.
In addition, the number of operations of the mirror mechanism 71 is written in the EEPROM 73.

The exposure monitor circuit 74 includes a photographic film 46.
Light receiving element for receiving the subject light reflected by the photographic film, and a photographic film 4 based on the subject light based on the photoelectric signal from the light receiving element.
6 is obtained by integrating the exposure amount, and the integrated value is used as the body M
The PU 80 includes an integrating circuit and the like. The main body MPU 80 obtains a difference between the exposure amount due to the subject light at the time of shooting and the standard exposure amount based on the integrated value from the exposure monitor circuit 74,
When the difference is large, a warning display of abnormal exposure is displayed on the liquid crystal panel 39 of the main body 8, for example.

The drive circuit 75 drives the diaphragm device 17 and the shutter device 18 of the lens unit 5. Drive circuit 75
Controls the drive current flowing through the solenoid 63 to open and close the shutter blades 18a, and also controls the lock mechanism 65.

The timer 76 is controlled by the main body MPU 80. At the time of photographing, the timer 76 is reset immediately before the shutter blade 18a opens and closes for exposure, so that the timer value T becomes "0". The timing starts when the interrupter 20 generates the detection signal. As a result, the time from when the shutter blade 18 a is detected by the photo interrupter 20 is measured by the timer 76. At the time of exposure, the main body MPU 80 determines the timer value T of the timer 76 and the EEPROM value of the lens unit 5.
The delay time Td read from the OM 19 is compared.
In this comparison, the moment the timer value T matches the delay time Td, the main body MPU 80 sets the sync switch 39
Is turned ON.

An external strobe device 82 is connected to the sync contact 39a as required, as described above. A flash device 82 is connected to the sync switch 39 via the sync contact 39a, and a sync signal is sent to the flash device when a delay time Td has elapsed since the shutter blade 18a was detected by the photo interrupter 20. Accordingly, when the shutter blade 18a is fully opened regardless of the detection error of the photo interrupter 20, the strobe light of the strobe device 82 is emitted in response to the synchronization signal.

In this example, the EEPROM 19 in which the delay time Td is written as described above serves as the adjusting means. The EEPROM 19, the photo interrupter 20, the timer 76, the synchro switch 38 and the main body M
The PU 80 constitutes a synchro signal generator. The sync switch 38, the main body MPU 80, the timer 7
Reference numeral 6 denotes a synchronizing signal generating means. If the synchronization signal generation timing does not require much precision, the configuration may be such that the synchronization signal is generated at the timing when the detection signal from the photo interrupter 20 is generated.

As described above, the synchro signal generator is composed of a small number of components and generates a synchro signal at an accurate timing. The delay time T
Since d can be rewritten after manufacturing, it can be easily adjusted even when the generation timing of the synchro signal is out of order. Further, since it is detected in a non-contact manner that the shutter blade 18a has fully opened the shutter opening, the opening / closing operation of the shutter blade 18a is not affected.

The film holder 4 has a winding mechanism 5 in addition to the winding mechanism 51 and the liquid crystal display 55 described above.
An EEPROM for a holder for storing the number of operations of 1 and a holder MPU as a control circuit for controlling these circuits are incorporated. When the film holder 4 is mounted on the camera main body 3, communication is performed between the holder MPU and the main body MPU 80, and each part of the film holder 4 is operated under the control of the main body MPU 80.

The lens unit 5 is provided with the diaphragm device 1 described above.
7, a shutter device 18, an EEPROM 19, and a photo interrupter 20 of the shutter device 18 are incorporated.
These are operated by power supply and control from the main body 8. The shutter device 18 includes a shutter blade 18a at the time of exposure, in addition to a detection signal from the photo interrupter 20 at the time of photographing.
Returns to the shielding position, and an SEE signal indicating that the exposure is completed, and S indicating that the shutter blade 18a is at the shielding position.
An EC signal, an ST signal indicating that exposure has started, and the like are output. Note that these signals are generated based on the operation of the actuator 18b. Also, signals such as the open aperture value and the set aperture value are sent from the aperture device 17 to the main body MPU 80. Note that, in practice, the aperture device is 1
7 is integrated with the shutter device 18.

In the EEPROM 19, the number of operations of the shutter device 18 is updated by the main body MPU 80 every time exposure is completed. Immediately before the start of exposure, the EEPROM 19
, The delay time Td is read out by the main body MPU 80.

Next, the operation of the above configuration will be described with reference to FIG. At the time of photographing, the film holder 4, the lens unit 5, and the AE finder or the waist level finder 6 loaded with the photographic film 46 are mounted on the camera body 3. Also, when the subject brightness is low, etc.
The strobe device 82 is connected to the synchro contact 38a.

The photographer operates the mode changeover switch 34 to select one of the winding modes. Then
The main power switch is turned on, and the circuits in the camera body 3 and the body MPU 80 are activated. Also, the contact portions 22, 21, 52, 53 are provided from the power supply circuit of the camera body 3.
Is supplied to the lens unit 5 and the film holder 4 via the. Of course, when the AE finder is mounted, power is also supplied to the AE finder.

With this power supply, the lens unit 5
The aperture device 17, the shutter device 18, and the EEPROM 19 become operable, and the photo interrupter 2
0 is driven, and the detection light is output from the light projector 20a to the light receiver 20b. Note that the photo interrupter 20 may be driven only while the shutter blade 18a is performing the opening and closing operation at the time of exposure.

When the main body MPU 80 is activated, the main body MPU 80 checks each part of the main body part 8, communicates with the film holder 4, further checks whether or not each signal is input from the lens unit 5, and can take a picture. Check whether the status is correct. Then, in a state where photographing is possible, a drive current is supplied to the solenoid 63 by the drive circuit 75 and the lock mechanism 65 is operated. As a result, the shutter blade 18a swings from the shielding position to the fully open position, and the shutter mechanism 18a is held at the fully open position by the lock mechanism 66 even after the drive current is stopped.

While the shutter blade 18a is held at the fully opened position, one of the shutter blades 18a enters between the light emitter 20a and the light receiver 20b of the photo interrupter 20, so that the "L" level is output from the photo interrupter 20. The state is where the photoelectric signal is output.

When taking a picture, the photographer must wear the AE finder or the waist level finder 6
Framing is performed using. Also, the lens unit 5
By operating the aperture lever 17c, the aperture value is set, and the shutter speed adjustment dial 33 is operated to set the shutter speed. In addition, AE finder is attached, AE
When the mode is selected, the shutter speed is automatically set in accordance with the set aperture value, subject brightness, and film sensitivity. Further, since the shutter blade 18a is swung to the fully open position regardless of the set shutter speed, it is possible to synchronize strobe light emission with all shutter speeds. Therefore, when performing flash photography using the flash device 82, it is not necessary to adjust the setting of the shutter speed for flash photography.

Thereafter, the photographer presses the release button 36 to perform photographing. When the release button 36 is pressed, a shooting case is performed according to the procedure shown in FIG. FIG. 8 shows the procedure of the main part, and some procedures are omitted.

When the release button 36 is pressed, the main body MPU 80 first checks the battery of the camera body 3. By this battery check,
When it is determined that the remaining battery level of the camera body 3 is small enough to perform shooting, the liquid crystal display 55 of the film holder 4 displays that the remaining battery level is low, and ends the shooting sequence.

When the battery level is sufficient, the main unit MP
U80 is the EEPROM of the attached lens unit 5
The delay time Td is read from the OM 19 and stored.
Thereafter, the lock by the lock mechanism 66 is released via the drive circuit 75. As a result, the connecting member 62 is
The shutter blade 18a is slid by the urging force of No. 4 to swing to the shielding position. Further, the shutter blade 18a is swung to the shielding position, and one of the shutter blades 18a is
The photoelectric signal from the photo-interrupter 20 becomes "H level" because it is retracted from between the light receiving device 0a and the light receiver 20b.

The main body MPU 80 receives the SEC signal output from the shutter device 18 and operates the shutter blade 18
is detected, the motor 72a is driven via the mirror drive circuit 72, and the light shielding plate 2 is driven.
5. The mirror 26 is turned from the DOWN position to the UP position. At the same time, the aperture device 17 is operated via the drive circuit 75, and the aperture blade 17a is stopped down to the aperture value set by the aperture lever 17c. Thereafter, main body MPU 80 resets timer value T of timer 76 to “0”.

After resetting the timer 76, the main unit MPU 80
Drives the drive current from the drive circuit 75 to the solenoid 63 of the actuator 18b to start photographing. Then, the connecting member 62 together with the plunger 63a is
, The shutter blades 18a are simultaneously swung in the opening direction from the blocking position. When the shutter blade 18a starts swinging in the opening direction in this way, the output ST
The signal is stopped. The main body MPU 80 starts counting the shutter time in response to the stop of the ST signal.

As the shutter blade 18a swings in the opening direction, the opening area of the shutter opening 66 gradually increases. When the shutter blade 18a reaches the fully open position, the shutter opening 66 is fully opened. After the shutter blade 18a reaches the fully open position, the main body MPU 80 stops the drive current of the solenoid 63 when the measured shutter time reaches a value corresponding to the set shutter speed.

When the driving current is stopped, the connecting member 62 is slid by the urging force of the spring 64, and the shutter blades 18a start swinging from the fully open position to the closing direction all at once, return to the shielding position, and return to the shutter opening 65. Close. And
When the shutter blade 18a returns to the shielding position, a SEE signal is sent from the shutter device 18 to the main body MPU 80 to notify that the exposure has been completed. The shutter blade 18a
Is swung in the closing direction from the fully open position depending on the set shutter speed.

As described above, the photographic film 46 is exposed by the subject light incident through the photographing optical system 16, the aperture opening, and the shutter opening 65 while the shutter blade 18a opens the shutter opening 66.

As described above, the main body MPU 80 monitors the input of the detection signal from the photo interrupter 20 during the opening and closing operation of the shutter blade 18a. For example, as described above, the opening and closing operation of the shutter blade 18a is performed without any trouble, the shutter blade 18a is swung to a substantially fully open position, and a part of the shutter blade 18a is
When the light enters between a and the light receiver 20b, the detection light from the light projector 20a is not received by the light receiver 20b.
As a result, the photoelectric signal from the photo interrupter 20 changes from “H level” to “L level”. Then, the change in the photoelectric signal is sent to the main body MPU 80 as a detection signal. Note that the timing at which the detection signal is generated at this time is not later than the timing at which the shutter blade 18a reaches the fully open position.
It changes depending on an assembly error of 0 or the like.

When the detection signal is input, the main body MPU 80
Starts a timer 76, and measures the time from the time when the detection signal is generated by the timer 76 as a timer value T. The main body MPU 80 starts counting time by the timer 76,
The timer value T is compared with the delay time Td previously read from the EEPROM 19, and if the former matches the latter, the sync switch 38 is turned on. Of course, when the delay time Td is “0”, the synchro switch 38 is turned on simultaneously with the input of the detection signal. Thereby, the synchro switch 38 is turned on when the delay time Td elapses from the time when the detection signal is generated, and when the strobe device 82 is connected to the synchro contact 38a, the synchro switch 38 is turned on. Strobe light emission is performed by the strobe device 82.

The delay time Td is defined as the time from when the detection signal is generated to when the shutter blade 18a actually reaches the fully open position.
Since the data is written in the OM 19, as a result, when the shutter blade 18a reaches the fully open position, the synchro switch 38 is turned on to perform strobe light emission, and the strobe light reflected by the object is transmitted to the fully opened shutter opening 66. Through the photographic film 46 as subject light. Since the flash is not emitted while the shutter blade 18a is swinging toward the fully open position or while the shutter blade is swinging from the fully open position to the blocking position, the flash photography is performed. There is no shortage of exposure when performing.

When the opening and closing operation of the shutter blade 18a is normally performed and the SEE signal is inputted, the main body MPU 80
Activating the mirror mechanism 71 via the mirror driving circuit 72,
The light shielding plate 25 and the mirror 26 are returned from the UP position to the DOWN position. Then, after that, the shutter blade 18a is swung to the fully open position and held at the fully open position, and the aperture is opened. Further, an instruction to feed the film is given to the film holder 4. The film holder 4 feeds the photographic film 46 by one frame in accordance with the instruction to feed the film.

On the other hand, while monitoring the input of the detection signal, the main body MPU 80 monitors the shutter time being measured, and determines whether or not this time exceeds the shutter time corresponding to the set shutter speed. Check repeatedly. And
If the detection signal is not input even if the shutter time corresponding to the set shutter speed is exceeded, for example, the shutter blade 18a is locked at the shielding position, or the shutter blade 1 is locked.
8a It is determined that some abnormality has occurred such as being locked or returning to the shielding position before reaching the fully open position.

When the above determination is made, the main body MPU 80
Sets an SC error flag in a register indicating that the full opening of the shutter blade 18a has not been confirmed, and
Instruct the film holder 4 to display a warning based on the error flag. Thereby, the mark corresponding to the lens unit 5 on the liquid crystal display 56 blinks, and a warning is given to the photographer.

In the above embodiment, the shutter blade opens the shutter opening separately provided, and the position where the shutter opening is fully opened is set as the fully opened position of the shutter blade. Is formed, or when the opening diameter of the shutter opening provided before or after the shutter blade is larger than the opening diameter formed by the shutter blade, the opening diameter formed by the shutter blade becomes the maximum. The position of the shutter blade at that time is the fully open position.

In the above embodiment, the EEPROM is used as the adjusting means, but other means may be used as the adjusting means. For example, the number of pulses generated at a constant period from the time of input of the detection signal from the photo interrupter is counted, and when the number of counted pulses reaches the number corresponding to the delay time of the shutter device, the sync signal or the sync signal is output. May be used. In addition, a voltage corresponding to the delay time of the shutter device is output using a variable resistor or the like, and this voltage is compared with a voltage that is gradually increased from the time when a detection signal is generated from the photo interrupter. , A sync signal can be generated when these voltages become equal.

In the above embodiment, a system camera in which a lens unit, a film holder and the like are mounted on a camera body has been described. However, the present invention can be used for various cameras such as an instant camera and a compact camera.

[0075]

As described above, according to the present invention,
In the process of moving the shutter blade in the opening direction, the photo interrupter photoelectrically detects that a part of the shutter blade has moved between the light emitter and the light receiver, and in response to the detection signal from the photo interrupter at this time, the synchronization is performed. Since the signal is generated, the number of components can be reduced, and the opening / closing operation of the shutter blade itself is detected without affecting the opening / closing operation of the shutter blade, and a synchro signal is generated in response thereto. be able to.

Further, the photo interrupter is arranged so that the detection signal is output before the shutter blade reaches the fully opened position, and after a delay time corresponding to the individual difference of the shutter device from the time when the detection signal is received, Since the sync signal is generated, the sync signal can be accurately generated at the timing when the shutter blade reaches the fully open position.

[Brief description of the drawings]

FIG. 1 is a graph showing a movement position of a shutter blade and a change in a detection signal and a sync signal from a photo interrupter.

FIG. 2 is a perspective view showing the appearance of the camera.

FIG. 3 is a sectional view showing a main part of the camera.

FIG. 4 is a perspective view illustrating a configuration example of a shutter device.

FIG. 5 is an explanatory diagram showing a state in which a shutter blade is at a fully open position.

FIG. 6 is an explanatory diagram showing a state where a shutter blade is at a shielding position.

FIG. 7 is a block diagram illustrating an electrical configuration of the camera.

FIG. 8 is a flowchart illustrating a procedure of processing performed at the time of photographing.

[Explanation of symbols]

 2 Camera 3 Camera Body 5 Lens Unit 18 Shutter Device 18a Shutter Blade 19 EEPROM 20 Photo Interrupter 20a Projector 20b Receiver 38 Synchro Switch 38a Synchro Contact 76 Timer 80 Main Unit MPU

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Katsuhiko Yamamoto 1-324 Uetake-cho, Omiya-shi, Saitama Fuji Photo Optical Machine Co., Ltd. (72) Inventor Hisashi Hamada 3-13-45 Izumi, Asaka-shi, Saitama Within Film Co., Ltd. (72) Inventor Tokuji Sato 3-13-45 Izumi, Asaka-shi, Saitama Fuji Photo Film Co., Ltd. F-term (reference) 2H053 AD03 BA78 2H081 AA48 BB16 BB22 CC62 DD00 2H082 CC03 CC17 CC27 CC38

Claims (2)

[Claims] 1. A shutter device having a shutter blade that moves in an opening direction in response to a shutter release and fully closes after reaching a fully open position, and emits strobe light when the shutter blade reaches a fully open position. A synchro signal generating device for generating a synchro signal for use, comprising: a light emitter and a light receiver arranged so as to sandwich the movement path of the shutter blade, and a part of the shutter blade moves in a process of moving the shutter blade in an opening direction. A photo-interrupter that photoelectrically detects that it has moved between the light-emitting device and the light-receiving device and outputs a detection signal; and a synchro signal generation unit that generates the synchro signal in response to the detection signal from the photointerrupter. A synchro signal generator comprising: 2. The photo interrupter is arranged at a position where the detection signal is output before a shutter blade reaches a fully open position, and the sync signal generating means includes:
2. The synchronizing signal according to claim 1, further comprising means for adjusting a delay time according to an individual difference of the shutter device, wherein the synchronizing signal is generated after a lapse of a delay time by the adjusting means from the time when the detection signal is received. Signal generator.