JP2837686B2 - Exposure control device for variable focus camera - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application field The present invention can change the focal length, for example,
More particularly, the present invention relates to an exposure control device for a lens shutter type variable focus camera in which the aperture diameter at the time of full opening changes according to a change in the focal length.

[Prior Art] Generally, in a variable shutter camera of a lens shutter type, a type of lens whose F value changes by a zooming operation is used due to design or cost restrictions. However, when this type of lens is used, there is a drawback that a difference occurs in the resolution when the lens is opened depending on the focal length.

To address this issue, Japanese Patent Application No. 63-55011 discloses a variable-focus camera exposure control device that regulates the aperture diameter at the time of full opening in accordance with the focal length so that a substantially constant resolution can be obtained at any focal length. It has been proposed.

[Problem to be Solved by the Invention] In the above-described conventional exposure control device for a variable focus camera,
The time from the start of opening of the shutter blade to the opening thereof varies depending on the focal length. For this reason, not only the open waveforms are not the same, but also the proportional relationship is lost, and the correction for the exposure calculation according to the focal length has become serious. Accordingly, an object of the present invention is to provide an exposure control device for a variable focus camera that can simplify exposure calculation.

[Means for Solving the Problems] In order to achieve the above object, in an exposure control device for a variable focus camera according to the present invention, a variable focus camera having a sector that can be used both as an aperture and a shutter and has a variable opening / closing speed. Detecting means for detecting a focal length of the photographing lens in a camera having a photographing lens, and opening restricting means for setting an opening F value which is regulated based on the aperture of the sector according to the detected focal length. Setting means for setting the opening / closing speed of the sector; and controlling the setting means in accordance with the set opening F value so that the time from the start of opening the sector to the opening diameter is substantially constant. Control means for performing the operation.

[Operation] According to the present invention, the aperture waveform has a proportional relationship even if the diaphragm changes according to the focal length, so that the exposure calculation can be performed with the time until the aperture being opened constant. Things.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 schematically shows the configuration of an exposure control device according to the present invention.

In FIG. 1, when a zooming operation is performed by the zoom means 44, the focal length is changed accordingly. Then, the focal length is detected by the focal length detecting means 43, and the detected focal length information (zoom value) is transmitted to the control means.
41, throttle control means 42 at full open, brake time calculation means 4
5, and the driving voltage calculation means 46, respectively.

At the start of the shutter control, when the control means 41 sets a high drive voltage required for charging by the drive voltage setting means 35 and selects the normal rotation means 38 by the selection means 36, the control means 41 operates as a shutter blade. Driving of the sector 32 is started. Then, the sector 32 is moved, and charging is completed by contact with a magnet described later. Then
This is detected by the charge completion detection means 34, and the detection signal is supplied to the control means 41.

When the detection signal is supplied from the charge completion detection means 34, the control means 41 selects the brake means 39 by the selection means 36. Further, based on the focal length information from the focal length detecting means 43, different brake times are set in the brake time timer 40. Then, according to the brake time set in the brake time timer 40, the brake means 39 applies a brake to a shutter motor (not shown) for quickly reducing the speed from the charge speed to the release speed. In this case, the braking time is changed according to the focal length, and the braking time according to the focal length is obtained by the braking time calculating means 45. That is, the braking time is
Using data from the tele and wide brake time tables 47a and 47b of an E ² PROM (electrically erasable programmable read only memory) 47, based on the focal length information from the focal length detecting means 43, Is obtained by interpolation.

When the control means 41 detects that the braking time has elapsed, the selection means 36 selects the normal rotation means 38 again. Then, a sector drive voltage corresponding to the focal length information is sent to the drive voltage setting means 35. In this case, the sector drive voltage is obtained by the drive voltage calculation means 46. That is, the drive voltage can be obtained by interpolation based on the focal length information from the focal length detection means 43 using the data from the tele and wide drive voltage tables 47c and 47d of the E ² PROM 47. ing.

The sector 32 starts to open at a speed corresponding to the focal length. Then, when the opening of the sector 32 is detected by the shutter opening detecting means 33, the detection signal is supplied to the control means 41. At this time, the throttle at the time of full opening is regulated by the throttle regulating means 42 at the time of full opening.

In this way, when the detection signal from the shutter open detection means 33 is supplied to the control means 41, the selection means 36
37 is selected. The exposure is performed by maintaining the opening of the sector 32 by the opening means 37.

As described above, while restricting and changing the aperture at the time of full opening according to the focal length information, and changing the drive voltage of the sector according to the focal length information, the speed until the sector is opened is changed. I have to. Therefore, irrespective of the focal length, the time from the start of the sector opening to the full opening (opening) can be made constant.

FIG. 2 shows a schematic configuration of a variable focus camera to which the present invention is applied. That is, the CP of the camera body 10
A U (Central Processing Unit) 11 controls the operation of the entire camera including the above-described exposure control. The CPU 11 is supplied with the ISO sensitivity information of the film 12 by the DX code input unit 13 and the subject luminance information of the subject 14 by the photometry unit 15, respectively. Further, the current position information (zoom value) of the zoom (for the zoom means 44 in FIG. 1) 16 is supplied from a zoom encoder (corresponding to the focal length detecting means 43 in FIG. 1) 17. Based on these three pieces of information, data necessary for shutter control, such as seconds, is calculated in the CPU 11.

The shutter is an open stop (a stop restricting means 42 when fully opened in FIG. 1) that regulates the opening diameter when the shutter is opened according to the position of the zoom 16.
18, a sector 32 linked to a shutter motor (to be described later), a photo interrupter (hereinafter abbreviated as PI) 20 for detecting the opening and closing of the sector 32, and the sector 32
(Hereinafter, abbreviated as Mg) 21 and a charge completion detecting means 34
An AE (auto exposure) switch (hereinafter abbreviated as AEsw) 22 is provided.

The PI20 detection signal is sent to the photo interrupter input
It is supplied to the CPU 11 via 26.

The Mg 21 is transmitted to the CPU 11 via the magnet control unit 24.
Is controlled by

The AEsw22 is turned off from on when a gear (not shown) is rotated to a position where Mg21 can be adsorbed, and turned on when the sector 32 is fully opened. The AEsw 22 on / off signal is supplied to the CPU 11 by the AEsw detection unit 25.

When a shutter motor (not shown) is rotated by the CPU 11 via the motor control circuit 23, the gear is rotated to a position where the Mg 21 can be attracted, thereby turning off the AEsw22. And, through the magnet control unit 24, Mg21
Is turned on, the sector 32 starts to open according to the rotation of the shutter motor. Here, open aperture with zoom 16
Since the aperture diameter of the aperture 18 differs, the time until the sector 32 is opened is made equal by changing the drive voltage of the shutter motor according to the focal length. When the sector 32 is opened, the brake is applied to the shutter motor to stop the rotation, and the Mg 21 is skipped as time elapses according to the F value of the shutter (hereinafter abbreviated as F No.).

In the CPU 11, the distance to the subject 14 measured by the distance measuring unit 28, the ISO sensitivity information, and the Mg 21
The emission time of the strobe 19 is determined by the F No. when the camera is skipped and the charging voltage of the main capacitor. Then, according to the light emission time, a strobe light emission control circuit
By controlling 27 and changing the guide number of light emission (hereinafter abbreviated as G No.), proper exposure is performed.

FIG. 3 and FIG. 4 schematically show the main parts of the mechanical mechanism of the shutter.

In FIG. 3, reference numeral 51 denotes an AE gear, which is rotated by a shutter motor 61 shown in FIG. Reference numeral 52 denotes a seesaw member.
Is rotated about a fulcrum A by contact of a pin provided on the AE gear 51. At one end of the seesaw member 52, an urging force by a spring 57 is urged inward in the drawing, and an open / close pin 56 for opening and closing the sector 32 is provided at the other end. Reference numeral 53 denotes an AE idle gear, and reference numeral 54 denotes a charge gear. The rotation of the AE gear 51 is transmitted to the charge gear 54 by the AE idle gear 53. Reference numeral 55 denotes a Mg arm. The Mg arm 55 is a fulcrum B which is pivotally supported by the contact of the cam surface of the charge gear 54.
Is rotated around the center. One end of the Mg arm 55 is formed integrally with the rotation center (fulcrum A) of the seesaw member 52, and the other end thereof is urged by a spring 58 in a flying direction (upward direction in the drawing). ing. 59 is an armature provided at the other end of the Mg arm 55,
After the armature 59 is applied to the Mg21, the Mg21
Is attracted by the energization of.

In FIG. 4, reference numerals 32, 32 denote a pair of sectors, each of which is rotatably supported by pins 32b, 32b. Each of the sectors 32, 32 has a long hole 3
2a, 32a are formed, and the opening / closing pin 56 is inserted into the overlapping portions of the elongated holes 32a, 32a. That is, the sectors 32, 32 are opened and closed around the respective pins 32b, 32b by the vertical movement of the open / close pins 56. Also. The output of the PI 20 is changed according to the opening and closing of the sectors 32,32.

Here, the operation of the shutter mechanism in the above configuration will be described. For example, as shown in FIGS. 3 (a) and 4 (a), when the sectors 32 and 32 are closed, It is assumed that the motor 61 is driven. Then, according to the rotation of the shutter motor 61, the AE gear
The 51 and the charge gear 54 are rotated one to one.

As a result, as shown in FIG.
The Mg arm 55 is charged by the cam surface of
The armature 59 and Mg21 are mechanically applied. At the same time, the seesaw member 52 is charged by the pin of the AE gear 51, and the sectors 32, 32 are prevented from opening. In this case, when the rotation center of the seesaw member 52 is moved by the charging of the Mg arm 55, the sectors 32 and 32 are opened,
The movement of the rotation center is corrected by charging the seesaw member 52.

On the other hand, immediately before the charging of the Mg arm 55 is completed, the state of the AEsw22 (not shown) is changed from ON to OFF. With this change, the energization of Mg21 is started, so that the armature 59 is adsorbed by Mg21.

In this state, one end is braked to the shutter motor 61, and thereafter, the shutter motor 61 is driven again by the sector driving voltage. By changing the voltage for driving the sector according to the focal length. Sector 32,3
The time from the start of opening 2 to the opening of the sectors 32, 32 until the aperture stop is fixed.

That is, when the shutter motor 61 is further driven by the sector drive voltage from the charge completion state shown in FIG. 3B, the AE gear 51 is rotated with the rotation. Then, as shown in FIG. 3 (c), the seesaw member 52 is rotated following the rotation of the AE gear 51, and the open / close pin 56 is moved upward. This opens the sectors 32, 32 as shown in FIG. 4 (b).

Normally, when the sectors 32 and 32 are closed, as shown in FIG.
I.20 is designed to shield light. Sector from this state
When the windows 32 and 32 start to open, as shown in FIG. 4 (b), the leading end thereof comes off the PI 20, so that the light is changed from light shielding to light transmitting. However, the fact that sectors 32 and 32 are actually opened is
After the PI20 changes to light transmission, it moves a certain distance.

On the other hand, in a state where the sectors 32 and 32 are open, Mg2
It is assumed that the energization of 1 is stopped, that is, Mg21 is skipped. Then, the Mg arm 55 is moved upward by the spring 58,
This movement causes the open / close pin 56 of the seesaw member 52 to move downward. As a result, the sectors 32, 32 are closed from the open position shown in FIG. 4B to the closed position shown in FIG. 4A.

If the armature 59 cannot be sucked due to the disconnection of the Mg 21 or the like, the sectors 32 are not opened. When the sectors 32, 32 are stopped during opening, the shutter motor 61 is braked. Furthermore, when the second time does not reach the opening, that is, when closing the sectors 32, 32 during the opening,
In the same manner as described above, this is performed by stopping the current supply to Mg21.

Next, the aperture waveform, that is, the waveform of the amount of light passing through the lens will be described.

FIG. 5 shows an aperture waveform at the time of telephoto when the sector drive voltage is 3V. The open aperture in this case is the same as the fully open sectors 32,32. Therefore, sectors 32, 32
Is the shutter open waveform as it is.

FIG. 6 shows an aperture waveform at the time of widening. In the case of wide, the magnification is smaller than that of telephoto, and conversely, the amount of light increases, and the aperture waveform increases as shown by the broken line in the figure.
However, in order to increase the depth of field at the time of opening, the opening of the sectors 32, 32 is stopped during the opening. Therefore, when the sectors 32, 32 are driven at the same drive voltage (for example, 3V), the time until the opening of the tele becomes shorter than the time until the opening of the wide. For this reason, the calculation for the exposure time is complicated.

In view of this, the sector drive voltage at the time of widening is set lower than that of telephoto, and as shown by the solid line in the figure, the time To until opening is made constant irrespective of the focal length. This makes it possible to easily calculate the exposure time.

That is, assuming that the current focal length information is Z _M and the tele and wide focal length information is Z _T and Z _W respectively,
By approximating by the braking time calculation means 45 in a straight line, the brake time, brake time = (Z _T -Z _M) × wide braking time + (Z _M -Z _W) calculated easily from the brake time × telephoto it can. However, the tele and wide brake times are data supplied from the tele and wide brake time tables 47a and 47b of the E ² PROM 47, respectively.

Similarly, the sector drive voltage, the driving voltage calculation unit 46, can be easily calculated from the driving voltage = (Z _T -Z _M) × wide drive voltage + (Z _M -Z _W) × driving voltage of tele . However, the tele and wide drive voltages are data supplied from the tele and wide drive voltage tables 47c and 47d of the E ² PROM 47, respectively.

The value calculated in this manner, for example, the sector drive voltage is converted into a voltage by the D / A conversion means 72 shown in FIG. This voltage signal is supplied to the base of the transistor 74 via the operational amplifier 72. The power supply voltage Vcc is supplied to the collector of the transistor 74 via the resistor 73. Therefore, by controlling the base voltage of the transistor 74 by the voltage signal, the shutter motor 61 is driven by the bridge circuit. in this case,
The potentials at the points α and β are the same due to the imaginary short. For this reason, a constant drive voltage is maintained regardless of the load fluctuation of the shutter motor 61.

FIG. 8 shows a timing chart at the time of shutter control.

First, the drive of the shutter motor 61 is started at a high voltage of, for example, 3 V in order to shorten the time for charging the Mg arm 55.

Then, immediately before the charging of the Mg arm 55 is completed, if the state of AEsw22 is changed from on to off, the shutter motor 61
The brake is applied only for the braking time (AEBRKD) according to the focal length. Thereafter, the shutter motor 61 is driven again by the sector drive voltage (SECTRV) determined from the focal length.

On the other hand, immediately before the sectors 32 and 32 are released, PI2
When the state of 0 is changed from light-shielded to light-transmitted, the elapse of the trigger time (AETRGB) according to the focal length is waited, and when the shutter time elapses, the Mg 21 is turned off. During this time, when the opening of the sectors 32, 32 is detected by turning off the AEsw 22, the brake is applied to the shutter motor 61, whereby the sectors 32, 32 are stopped in an open state.

Further, in this embodiment, the strobe light 19 is emitted as necessary within the Mg21 disconnection delay time (time from when the Mg21 power supply is stopped to when the Mg21 actually starts to be disconnected). Therefore, the F No. at the time of flash emission is the F No. when the Mg 21 is stopped, and the G No. of the flash 19 based on this F No., the distance information to the subject 14 and the ISO sensitivity information of the film 12. Is determined. In this case, strobe 19
For example, assuming that the battery can be charged up to 330 V, the relationship between the light emission time at 330 V and the G No. corresponds one-to-one. For this reason, the light emission time can be determined in reverse from the G No., and the actual light emission is controlled based on this.

FIG. 9 is a timing chart showing a series of release sequences by operating the shutter button.

When a release switch (hereinafter abbreviated as release sw) is turned on by operating a shutter button, first, a lens extending operation is performed. Next, the shutter motor
A shutter charging operation by 61, an exposure operation by opening and closing the sectors 32, 32, a one-frame winding operation of the film 12, and a lens reset operation are sequentially performed.

When the red-eye reduction mode is provided,
Prior to the exposure operation, a predetermined number of pre-emissions are performed at regular intervals. In the red-eye reduction mode, the pupil of the subject 14 is reduced by the pre-emission, so that red-eye occurring during the main emission is less likely to appear.

Specifically, first, one pre-light emission is performed, and then the lens is extended by a lens motor. Thereafter, the pre-emission is performed 11 times every 50 ms, and every 50 ms while the shutter motor 61 is charging the shutter. For example, shutter charge time is 50ms
Once for ~ 100ms, 2 for 100ms ~ 150ms
Each time, light is emitted. Then, when the charging operation is completed, light is emitted again, and the operation is shifted to an exposure operation.

Since the light emission G No., light emission interval, and light emission frequency of the pre-light emission greatly affect the reduction of red-eye, it is necessary to perform the pre-light emission even during the charging operation of the shutter. Therefore, in the present embodiment, a timer of 50 ms is run during the shutter charging operation, and the pre-emission is performed every 50 ms in parallel with the charging operation.

Next, the light emission operation of the strobe 19 in the multiple light emission mode will be described with reference to FIG. 10 and FIG.

In the multi-emission mode of this embodiment, as shown in FIG. 11 (a), four light emission operations are performed at intervals of 50 ms at the time of opening.

FIG. 10 (a) shows a strobe when the charging voltage is 330V.
19 shows the relationship between the charging voltage of the main capacitor 19 and the light emission time. Light intensity, that is, G No. of strobe 19
Is proportional to the capacitance of the capacitor and the square of the charging voltage.

Therefore, to make the same G No. for all four flashes,
The light emission time is, for example, 88 μs, 128 μs, 190 μs, 300 μs,
It needs to be longer later. Where strobe 19
Has a minimum light-emitting voltage, and light is not emitted at a voltage lower than the minimum voltage. For this reason, the charging voltage at the time when the fourth light emission is performed becomes the minimum light emission possible voltage (for example,
Attention must be paid to the setting of each emission time so that it does not fall below 190V).

FIG. 11 shows the timing between the light emission and the charging voltage.

Also, as shown in FIG. 10 (b), when the charging voltage is initially only 260 V, for example, the respective light emission times are set such that the G Nos. Has become. Incidentally, the light emission time when the charging voltage is 260 V is set to, for example, 48 μs, 56 μs, 66 μs, and 78 μs.

The charging voltage is, for example, 260V to 310V.
V, 310V to 330V may be divided into two cases as 330V, or may be finely classified. Further, in the present embodiment, only the charging voltage is considered, but the F No.
The G No. may be determined based on the distance to the subject 14 and the ISO sensitivity of the film 12, and the light emission time may be determined based on this.

The flowchart in FIG. 12 shows a series of processing "REL" from the time when the first release sw is turned on to the time when the first release is released.

At the time of photographing, when the first release sw is turned on, first, the distance measurement by the distance measurement unit 28 and the photometry by the photometry unit 15 are performed.

Based on these distance measurement information and subject brightness information, the CPU1
The extension amount of the lens is calculated by 1.

At this time, since the zoom position is already known from the focal length information (zoom value) from the zoom encoder 17, the feed amount correction by the zoom 16 is also performed. Here, the logarithmic compression value Dv (Dv
= Log ₂ d ² ).

The aperture value (Av) at the time of opening according to the zoom value is
Substituted into open aperture value Avo (apex display). This open aperture value Avo is changed by the focal length.

Next, the logarithmic compression value (second shutter time T
v) is substituted for Tvo of the open shutter time (corresponding to 24 ms in the opening waveform of FIG. 8A).

Further, a correction value (TvSFT) of the shutter time Tv is added to the open shutter time Tvo. Normally, this correction value is “0”
It is. However, in the case where the shutter cannot be adjusted mechanically in the production of the shutter, the adjustment using the correction value can be performed.

Subsequently, an exposure value input Ev (Ev = Bv + Sv) is obtained by adding the subject brightness information Bv from the photometry unit 15 and the ISO sensitivity information Sv from the DX code input unit 13.

Further, a correction value (EvSFT) of Ev is added to the exposure value Ev, as in the case of the open shutter time Tvo.

When the open aperture value Avo and the open shutter time Tvo are obtained, the open waveform of the shutter can be understood from these, so that the open aperture value Avo, open shutter time Tvo, and exposure value can be understood.
Seconds are calculated from Ev.

Subsequently, permission / prohibition of the main light emission and permission / prohibition of the pre-light emission in the red-eye reduction mode are determined. That is, the light emission flag and the pre-light emission flag are set to “1” when the strobe light is emitted, and are set to “0” when the light emission is prohibited. Therefore, the respective flags are set to "1" in the multi-flash mode and the forced flash mode, and to "0" in the strobe off mode.

In the normal mode and the red-eye reduction mode,
That is, when the mode is not the multi-flash mode, the forced flash mode, or the strobe off mode, the time of camera shake is calculated according to the zoom value. The reason why the camera shake time differs depending on the zoom value is that the depth of field differs due to the difference between the FNo. And the focal length at the time of opening depending on the zoom value, and the time possible due to camera shake differs depending on the zoom value. is there.

Then, the actual second time and the camera shake time are compared (second time> hand shake time).

As a result of this comparison, if the actual time is later than the camera shake time (low speed), the actual time is changed to the camera shake time.

 Further, the light emission flag is set to “1”.

Further, in the red-eye reduction mode, the pre-emission flag is also set to “1”.

On the other hand, if it is determined that the actual time is faster than the camera shake time (high speed), it is determined whether or not the subject is backlit.

At the time of shading, the light emission flag is set to “1” as in the case of low luminance.
Is set to

In the red-eye reduction mode, the pre-emission flag is also set to “1”.

Subsequently, it is determined whether or not the charging voltage of the strobe 19 is equal to or higher than 260 V (charging voltage ≧ 260 V).

When the charging voltage is equal to or lower than 260 V, the light emission flag and the pre-light emission flag are set to “0”, and light emission is prohibited.

After confirming the charging voltage of 260 V or more, the trigger time, that is, the time from when the state of the PI 20 changes from light-shielded to light-transmitted until the sectors 32 and 32 are actually opened is calculated. In this case, the drive voltage of the sectors 32, 32 is low in the wide state and high in the telescopic state. For this reason, the trigger time is minimum in telephoto and maximum in wide, but varies due to mechanical assembly and the like, and the respective values are different for individual shutters. Therefore, the difference between the maximum value and the minimum value (the difference between the tele and the wide) and the minimum value (the value of the tele) are respectively stored in the E ² PROM.
47, and the intermediate zoom value is obtained by interpolation.

When the trigger time is obtained, the actual shutter control time is obtained from the sum of the trigger time and the previously obtained time.

Also, the actual release time is obtained based on the trigger time.

Subsequently, the value Gv of the G No. is calculated. The value Gv of this G No.
Is the open Av value (Avo) and the logarithmic compression value D of the square of the distance
v, ISO sensitivity information Sv, open Tv value (Tvo), and Tv in seconds
It is determined from the value (Tvs).

Further, a correction value is added to the value Gv of the G No. obtained above. This addition of the correction value enables an appropriate G No. to be obtained even when the characteristics of the xenon tube constituting the strobe light 19 are slightly changed, for example. That is, the relationship between the G _V value G _V x of the light emission time T _FL and the time at which to emit light at 330V, expressed in _{G V x = f (T FL} ), the inverse function T _FL = f ^-1 ( In this embodiment, a table corresponding to G _V x) is provided.

Usually, the deviation of the G No. from the design value is often caused by a deviation of a xenon tube or a reflector. Therefore, G No.
Deviates proportionally, that is, the design value is GNx and the actual value is G
If Nx ', then GNx' = α.GNx. Here, α is a proportional constant.

Taking the logarithm by squaring both sides of the above equation, the ^{_{log 2 GNx '2 = log 2}} (α · GNx) 2 = log 2 GNx 2 + log 2 α 2. Converting this to G _V value, the _{G V x '= G V x} + C. Here, C = log ₂ α ² .

As a result, the emission time for obtaining the actual G No. is T _FL = f ^-1 (G _V x + C). Therefore, even if the G No. changes proportionally, G _V
It can be seen that the same table can be referred to by adding a constant value to the value.

Thus, the correction value C of G _V of values and fermentation time table and G _V, briefly herein can be adjusted characteristics of G No., correction values of Tv shutter time mentioned above (TvSF
T), exposure value Ev correction value (EvSFT), and G No. value Gv
Are written in the E ² PROM 47 which is a nonvolatile memory in the adjustment process at the factory.

Further, the emission time of the strobe light 19 is obtained from the value Gv of the G No.

Subsequently, the sector drive voltage and the brake time (eighth
The time of “AEBRKD” in the motor of FIG. These sector drive voltage and brake time are the difference between the minimum value and the maximum value stored in the E ² PROM 47 and the minimum value (tele and wide brake time,
Using telephoto and wide drive voltages), it is obtained by interpolation according to the zoom position.

As described above, when the first release sw is turned on, various values required for shutter control are obtained by calculation. Then, in this state, the process waits until the second release sw is turned on. At this time, a display process is performed.

When the second release sw is turned on, the pre-emission flag is determined. If the flag is “1”, the pre-emission is performed.

 Thereafter, the lens is extended.

Then, the pre-emission flag is further determined. If the flag is “1”, the pre-emission is performed 11 times every 50 ms.

Subsequently, exposure is performed according to a shutter control flow "SHUTR" described later.

When the exposure is performed, one frame of the film 12 is wound up. Further, the lens is reset to the initial position, and a series of release sequences is ended.

FIG. 13 shows a shutter control flow “SHUTR”.

First, the software pull-up of AEsw22 is turned on,
Port settings such as switching from output to input are performed.

 Further, the current limiting circuit of the motor drive circuit is turned on.

Then, a current of 1 A or more is prohibited from flowing to the shutter motor 61 and the like, and a voltage interrupt that generates an interrupt when the power supply voltage drops below 3.5 V is permitted.

Subsequently, according to the control flow “CHGGO” shown in FIG. 14, the shutter charge voltage of 3 V is set as the motor drive voltage. As a result, the shutter motor 61 is turned on, and the photo interrupter input
Circuits such as 26 are turned on.

Subsequently, according to the control flow “AEsw ON” shown in FIG. 15, it is determined whether the shutter is in the closed state based on whether the AEsw22 is at the low (L) level, that is, whether the shutter is ON. When this level is high (H), the process waits until the AEsw22 becomes L level. AEsw22 is a mechanical switch,
On chatter of about 1 ms occurs. For this reason, a 4-ms chatter killer is configured as software to detect the L level.

Also, at this time, the 1-second timer is run at the same time, and if the AEsw22 is set to the L level within 1 second, the AEsw flag is set to “0”.

The AEsw flag is determined. If the AEsw flag is "1", that is, if the AEsw22 does not become the L level within one second due to some abnormality, an error occurs and abnormal processing is performed.

On the other hand, if it is confirmed from the AEsw flag “0” that the shutter is in the closed state, a shutter charging operation is performed. Here, as shown in FIG. 8 (e), the charging operation is performed by a high voltage of 3V. And the above
It waits until AEsw22 changes from L to H level. In this case as well, the 1-second timer is run at the same time to determine the abnormality for 1 second. The off chatter of AEsw22 is about 200 μs.
For this reason, the L level is detected by a 1 ms chatter killer.

By running the 50 ms timer at the same time, when the pre-emission is required (when the pre-emission flag is “1”), the pre-emission is performed every 50 ms.

When the AEsw22 is set to the H level, that is, when the charging operation is completed, the energization of Mg21 is started. As a result, the Mg arm 55 can be adsorbed on Mg21.

Here, when the pre-emission flag is “1”, the pre-emission is performed again immediately after the Mg 21 is energized. With this pre-emission,
The time until the main light emission is shortened.

Subsequently, the shutter motor is driven for a time corresponding to the zoom value.
61 is braked. In the case of the present embodiment, the shutter charge operation is performed at a high voltage of 3V. In addition, by driving the sectors 32 and 32 at a high voltage of about 3 V during telephoto and at a voltage of about 2.2 V when wide, the sectors 32 and 32 are opened from the beginning of opening (the same aperture diameter as the open aperture 18). The time until it becomes constant is set regardless of the zoom value. However, the sector drive voltage (SE in FIG. 8 (e)) simply depends on the zoom value.
Just changing CTRV) will take too long for the speed to be constant. Therefore, in order to quickly stabilize the speed, after applying a brake for a time corresponding to the zoom value (corresponding to AEBRDK in FIG. 8E), the shutter motor 61 is driven by the sector drive voltage corresponding to the zoom value. Try to re-drive.

The reason why the voltage for charging is set as high as 3 V is that the charging time is shortened and the closing direction (the third
This is because a strong force is required to drive the Mg arm 55 pulled by the spring 58 in the opening direction (upward in the figure) in the opening direction (downward in FIG. 3). In addition, Mg arm 55 is Mg21
In this state, since a very strong force is not required for driving, it is possible to drive sufficiently with a low voltage. Specifically, the center value of the braking time is 0 m
s, 3ms for standard, 6ms for wide. The sector drive voltage is 3V for tele and 2.6 for standard.
V, wide and 2.2V. These values may be fixed values, or, as in the present embodiment, the tele and wide brake times and sector drive voltages corresponding to the characteristics of the individual shutters are stored in the E ² PROM 47 in order to increase the accuracy. In addition, the value between tele and wide may be obtained by interpolation.

Subsequently, re-energization of Mg21 is performed. This is because even if the output latch of the output port of the CPU 11 that controls the Mg 21 by the pre-emission is inverted, the Mg 21
Is to prevent the current from being turned off.

Thereafter, when the above-described braking time (AEBRKD) has elapsed, the control flow “EXPGO” shown in FIG.
Shutter motor with sector drive voltage according to zoom value
61 is driven.

Here, after the Mg21 is re-energized again, a 64 μs clock for time reproduction (the output is inverted every 64 μs) is started.

 Also, a one second timer is started.

Then, confirmation is made that the PI 20 is shielded from light. That is, when the charging operation is completed, the sectors 32 are still closed. Therefore, the PI 20 should be in the light-shielded state. Here, it is confirmed. Since the state is confirmed, the confirmation is performed again after elapse of 1 ms after the confirmation of the light shielding. In this case, if two consecutive shades are not confirmed within 6 ms,
An error is determined. In the present embodiment, the opening timing is monitored by the PI 20. Therefore, the failure of the PI 20 to operate properly is a fatal failure.

Therefore, if the light-shielding state of the PI 20 is not determined by the above confirmation, “1” is set to the damage flag (SHDMF).

 Then, the brake is applied to the shutter motor 61.

In this state, the damage flag (SHDMF) “1”
Abnormal processing is performed according to the determination of. This damage flag (SHDMF) is to perform an abnormal process when two errors occur. Therefore, if the damage flag (SHDMF) is "0", the damage flag (SHDM
After “1” is set in F), the above-described shutter control flow “SHUTR” is repeated from the beginning. However, Mg2
After one energization, the above-described abnormality processing is performed with one error.

On the other hand, when the sectors 32 and 32 are closed and the light shielding state is normally detected by the PI 20, the sectors 32 and 32 are closed.
Drive 2 is started. Then, the process waits until the PI 20 enters the light transmitting state.

When the PI 20 is in the light-transmitting state, the reproduction at the second time is started with the change in the state as a trigger. Also in this case, if the PI 20 is not brought into the light-transmitting state within one second, it is determined that an error has occurred. And the damage flag (SHDMF)
Is set to “1”, and after the shutter motor 61 is braked, the above-described abnormality processing is performed.

When the light transmission of the PI 20 is detected, a 2-second timer is started in addition to the previously started 64 μs clock. This two-second timer is used for compensating when the 64 μs clock is stopped by static electricity or the like.

The reproduction at the time is performed based on the output of the 64 μs clock. First, the control time is set in a 16-bit register BC. At this time, in the case of the multi-flash mode or the adjustment valve mode in which the checker (tester for assembling at the factory) is ON with the valve flag being “1”, the opening time is set in the register BC. Is done.
The valve flag is a flag for adjustment, and is set to “1” when the lens is adjusted in the open state.

The release time is set in the 16-bit register XA.

Here, the second time and the release time are the times including the trigger time from when the PI 20 is in the light-transmitting state to when the sectors 32 and 32 actually start to open, and are the resolution times of the 64 μs clock. is there.

The reason why the opening time is required for controlling the shutter is that the rotation of the AE gear 51 must be stopped. That is, even if the Mg arm 55 is attracted by the Mg 21, if the AE gear 51 is further rotated in the open state, the seesaw member 52 is also rotated. Therefore, the movement of the opening / closing pin 56 causes the sectors 32, 32 to be closed. Therefore, in order to maintain the opening, it is necessary to stop the rotation of the AE gear 51 by applying a brake to the shutter motor 61 in the opened state.

In this embodiment, the registers BC and XA are used as counters for reproducing the time, and are decremented each time the output from the 64 μs clock is inverted. As a result, when the second time is in the triangular region of the aperture waveform, a borrow occurs at the beginning of the second time, that is, the subtraction by the register BC. Also, when it is in the trapezoidal area, a borrow occurs at first in the open time, that is, the subtraction in the register XA.

When a borrow occurs in the subtraction in the register XA, the sectors 32, 32 are in an open state. For this reason, the brake is applied to the shutter motor 61, and the sectors 32, 32 are stopped.

In this state, when the valve flag is “1” and the checker is on, communication with the checker is continued. During communication with the checker, processing necessary for adjustment is performed. This process is performed according to the instruction code from the checker. Further, the valve mode for adjustment can be canceled by setting the valve flag to “0” by the command code.

After the shutter motor 61 is braked, it is sufficient to wait until the second time is set. For this reason,
The value of the register XA is set to the maximum value (XA> BC).

Thereafter, when the multi (light emission) mode is determined, the multi light emission operation is performed according to a processing flow “MULTS” for the multi light emission described below. In the case of this embodiment, in the open state, light emission is performed four times in total every 50 ms. When this multi-flash operation is completed, Mg
The process proceeds to a process for setting 21 to the non-energized state.

On the other hand, when a borrow occurs in the subtraction in the register BC, that is, when the time has elapsed, it is determined from the light emission flag whether or not to perform main light emission. In the case of the present embodiment, the main light emission is performed during a disconnection delay time (about 3 ms) from when the energization of Mg21 is turned off to when the Mg arm 55 is actually separated from the Mg21. Therefore, first, the current supply to Mg21 is turned off.

 Thereafter, the light emission time is set in the register XA.

Then, a control flow “FLUS
H, the main light emitting operation is performed. When the main light emission operation is completed, the process proceeds to a process for bringing Mg21 into a non-energized state.

By the way, when the 64 μs clock is stopped due to static electricity or the like during the reproduction at the time of the second time,
The output from the 2 second timer is substituted. In this case, the exposure is wrong, so it must be an error. However, since the exposure has been performed, it is possible to pass to the next processing without causing an error. This is because the probability that the 64 μs clock is stopped is extremely low, and it is considered that normal operation may be performed in the subsequent release operation, so that there is no need to perform abnormal processing such as locking the camera function. is there.

When the power supply to the Mg 21 is turned off, the state of the AEsw 22 is determined. If it is determined that the AEsw22 is at the H level, the shutter motor 61 is driven again by the charge voltage in accordance with the control flow "CHGGO" shown in FIG.

Then, according to the control flow “AEsw ON” shown in FIG. 15, the control waits until the level of AEsw22 becomes L. At this time, if the AEsw22 does not become the L level within one second, it is an error. However, in this case, only the damage flag (SHDMF) is set to “1”, and the abnormal processing is not performed. This is after the exposure has been normally performed, and if an error actually occurs, an error will occur again in the next release operation. Therefore, it is only necessary to perform the abnormal processing for the first time.

On the other hand, if it is determined that AEsw22 is at the L level, it means that the above-described shutter control has been performed normally. Thereby, “0” is set to the damage flag “SHDMF”.

When the damage flag (SHDMF) is set, the shutter motor 61 is braked.

Then, it waits until the AE gear 51 is completely stopped (for 50 ms). Thus, the shutter control ends.

Here, a summary of the error determination and abnormal processing in the shutter control described above is classified into three.

The first classification is an abnormality before the sectors 32 and 32 are opened, the second classification is an abnormality where it cannot be determined whether the sectors 32 and 32 are open or closed, and the third classification is normal exposure. The shutter does not return to the initial position after the operation is performed.

The first classification in the present embodiment corresponds to a case where the AEsw22 does not change from the H level to the L level within one second and the completion of the charging operation is not known. In this case, if this is the first error and the damage flag (SHDMF) is "0",
After setting the flag to “1”, the shutter control is restarted from the beginning. If this is the second error and the damage flag is “1”, an abnormal process is performed. Therefore, when the latch of the output port of an IC or the like is inverted by static electricity or the like, the port can be reset by starting over from the beginning, and normal control can be performed.

The second category is that PI20 does not change from shading to translucent,
This corresponds to a case where the timing for opening the sectors 32, 32 is not known. At this time, since the Mg 21 is already energized, the sectors 32 and 32 may be open and exposed, and the sectors 32 and 32 may remain closed due to disconnection of the Mg 21 or the like. This is a fatal error relating to the basic function of the camera, ie, taking a picture, because the CPU 11 cannot determine whether the exposure has been performed or not. In this case, a brake is applied to the shutter motor. In addition, abnormality processing is performed, and for example, all switches (including the release sw) other than the main switch are locked. This allows the user to know that an abnormality has occurred.

When the user intentionally turns on the main switch again, the switch is unlocked and the release operation is enabled. In this state, even if the release operation is instructed, there is a high possibility that the lock will be performed again. However, when an abnormality occurs due to dust or the like, it is possible to return to a normal state. Therefore, by releasing the lock by operating the main switch, it is possible to increase the chances of returning to the normal state.

The third category is that the AEsw22 is maintained even after the power to Mg21 is turned off.
Is not at the H level, and the AE gear 51 cannot be returned to the initial position. In this case, since the exposure is normally performed, the damage flag (SHDMF) is set to “1”.
, But does not perform any abnormal processing. By ending the shutter control as usual, one of the films 12 is
Wind up the frame and end shooting. If AEsw22 is abnormal, an error is determined in the next release operation, and abnormal processing is performed.

In this way, when an abnormality occurs in the shutter control, instead of simply locking the shutter, it is classified into three groups, and when the exposure is normally performed, the shooting of the frame is terminated. When the exposure cannot be performed normally, the lock can notify the user of the abnormality.

 Next, a flash-related control flow will be described.

FIG. 16 shows a control flow "FLUSH" for main light emission. When this flow is called, first, it is determined whether or not the charging voltage is 260 V or more. In this case, the voltage may be actually confirmed, or the determination may be made based on the already set flag. When the charging voltage is lower than 260 V (charging voltage> 260 V), light emission is prohibited.

If the charging voltage is determined to be 260 V or more, the light emission signal is set to H, and light emission is performed.

Then, according to the value (light emission time) of the register XA that has already been set, the process waits until the time of “XA value × 10 μs” elapses.

Thereafter, the light emission signal is set to L and light emission is stopped. That is, the strobe light 19 is emitted for the time of “XA value × 10 μs”.

At the time of the main light emission of the strobe light 19, the signal sent from the CPU 11 to the strobe light emission control circuit 27 is only the H or L signal.
In the strobe light emission control circuit 27, light emission is controlled by an IGBT, a thyristor, or the like based on the H / L signal.

FIG. 17 shows a control flow for the pre-light emission. The pre-light emission is basically the same as the main light emission, and only the light emission time (12 μs) differs from the case of the main light emission.

Fig. 18 shows the control flow "MULTS" for multiple flashes.
It shows. Charge voltage 310V for multiple flash
The light emission time can be changed depending on the above. That is, the charging voltage is 310 V or more (charging voltage 310 V)
In this case, the address of the table (described later) is changed, and “0” is set in the register E. The charging voltage is 310V
In the following cases, "3" is set in the register E.

Then, “3” is set in the register C, and a loop for emitting light four times is performed. Each time this loop is performed, “1” is added to the value of the register E.

In this state, it is determined whether or not the charging voltage is 260 V or more (charging voltage 260 V). According to this determination, if the charging voltage is 260 V or more, the processing flow “ML” shown in FIG.
According to “ML”, multiple light emission is performed.

In this processing flow “MLML”, of the light emission time obtained from the table (described later) according to the value of the register E, a time of 10 μs or more is stored in the register XA, and a fractional time of 10 μs or less (6 μs, 8 μs, 10 μs). ) Is set in the register B. First, 10 μm
Light emission is performed for a fractional time equal to or less than s hours. Then, after waiting for a time of “XA value × 10 μs” according to the value of the register XA, light emission is stopped. The light emission time in this case is obtained by the following equation.

 Emission time = (XA + 1) × 10 μs + B μs where B = 6,8, A (= 10).

On the other hand, when the charging voltage is 260 V or less, the above processing flow “MLML” is skipped.

In this embodiment, the charging voltage is set to two voltages of 310 V and 260 V.
Although it is divided into two parts, it is easy to increase the precision by dividing it into small parts.

FIG. 20 shows an example of a light emission time table referred to by the value of the register E. In this table, corresponding to the values (0 to 7) of the register E, the first to fourth shots at the time of full charge and the first to fourth shots at the time when the charge voltage is 310 V or less
Registers when the emission time of each shot is 88 μs, 128 μs, 190 μs, 300 μs and 48 μs, 56 μs, 66 μs, 78 μs
The value of XA and the value of register B are defined respectively.

Next, the calculation at the second time in this embodiment will be further described.

The shutter mechanism of this embodiment is a lens shutter that performs exposure by opening and closing the sectors 32, 32, as described above. The shape of the sectors 32, 32 is designed so that the opening waveform is proportional to the opening time (that is, the reciprocal of the square of F No.) until the opening waveform is obtained.

FIG. 21 and FIG. 22 show an example of the aperture waveform according to this embodiment. In the case of this embodiment, the time is determined by external light, and the influence of the light amount of the strobe light 19 is ignored.

Hereinafter, a case where the second time is obtained from the relationship between the exposure value Ev and the second time when there is a second time in the triangular area and the trapezoidal area will be described. Assuming that the required second time is Ts, in the triangular area,
The shaded area shown in FIG. 21 is the exposure amount, and Ev = Bv + Sv (1) (where Bv; subject brightness, Sv; the apex value of ISO sensitivity), and the area of the shaded area = exposure amount = 2- ^Ev Becomes This 2
^-Ev is from ^Fig.21 Can be represented by

By rearranging the logarithms of both sides, Ev = log ₂ Fo _(Z) ² -2 · log ₂ Ts + log ₂ Top-1 ... (2)

Assuming that the aperture value is Av and the open Av value is Avo from the conversion equation of the Apex calculation, Avo = log ₂ Fo _(Z) ² (3)

In addition, the shutter time is Tv, and the Tv value of 1/2 of the time is Tvs
Then,

 Further, assuming that Tvo value of 1/2 of the time until opening is Tvo,

 When these are substituted into the above equation (2), the following are obtained.

On the other hand, in the trapezoid region, the area of the hatched portion shown in FIG.
^{From -Ev} , it can be expressed as

By rearranging the logarithms of both sides, Ev = log ₂ Fo _(Z) ² −log ₂ (2Ts−To) +1.

By substituting the above equation (3) into this equation, Tvs = Ev−Avo (6) Are obtained respectively.

Since the triangular area and trapezoidal area are continuous, the exposure value at the γ conversion point
Ev can be obtained by eliminating Tvs from the above equations (4) and (6). That is, The second time may be simply obtained from the above equations (1) to (8). In the case of the present embodiment, a value TvSFT for correcting the Tv value until opening and a value E for correcting the exposure value Ev
The vSFT and vSFT are stored in the E ² PROM 47, and each is corrected at the time of calculation.

 From the above, the calculation for the second time is performed as follows.

1) Calculation of exposure value Ev: Ev = Bv + Sv + EvSFT + short distance correction 2) Judgment of area: Ev ≤ Avo + (Tvo + TvSFT) ... Triangle area: Ev ≥ Avo + (Tvo + TvSFT) ... Trapezoid area 3) Time of opening: To = 2 ^{( 1-Tvo-TvSFT)} 4) At the time of triangle: Tvs = 1/2 (Ev-Avo + Tvo + TvSF)
T): Ts = 2 ^(1-Tvs) 5) Trapezoid second: Tvs = Ev-Avo: Ts = 1/2 ｛2 ^{(1-Tvs) -To} ｝ Thus, the photometric value, that is, the subject brightness If the whole is under or over, or the lens is darker or brighter than the design value, the value EvSFT for correcting them at the factory adjustment is written to the E ² RPOM47.

Further, when the Mg21 disconnection delay time is longer or shorter than the design value, a correction value TvSFT for correcting the same is written at the factory.

Here, an example in which the Mg21 disconnection delay time is long,
This will be described with reference to the drawings.

In this case, the intended area abc is over the amount of bcd due to the cutting delay. Therefore, the Tv value at the time of opening is shifted by the correction value TvSFT of the shutter time Tv, and the time of opening is calculated as Te. As a result, the required area becomes aefh, and the time when the sectors 32, 32 close is Tf, which is earlier than the opening time To. Therefore, the actual area can be set to aij, and can be made equal to the target area abc. As a result, even when the opening time cannot be adjusted mechanically, the adjustment can be easily performed.

After the calculation, it is natural that the second time is kept within the range. The second time and the opening time used for actual shutter control are values obtained by adding the trigger time to these values.

Next, the calculation of the G No., that is, the Gv value at the time of the main light emission will be described with reference to FIGS. 24 and 25.

In this embodiment, the main light emission by the strobe light 19 is performed within the cut-off delay time of Mg21. For this reason,
The aperture value Av when opened is A when the sectors 32 and 32 are closed.
It can be considered a v-value.

Therefore, if the F No. at the time of light emission is F (x), the constant of the G No. Can be expressed as Where d is distance, G No. is guide number, s is ISO sensitivity of film, and s (100) is IS
O100 film sensitivity.

If both sides are squared to obtain the logarithm, log ₂ F (x) ² = −log ₂ d ² + log ₂ G No. ² + log ₂ s−log ₂ s (100).

Here, according to the apex conversion formula, Av = log ₂ F No. ² Dv = log ₂ d ² Sv = log ₂ s Gv = log ₂ G No. ²

Therefore, if the Sv value at ISO sensitivity = 100 is Sv (100), the following equation is obtained: Gv = Av (x) + Dv−Sv + Sv (100) (9)

Generally, the G No. at the time of main light emission is determined by the above equation (9), and the value of Av (x) differs depending on the triangular area or the trapezoidal area. That is, in the triangular area, from FIG. Becomes

 By taking the logarithm of both sides, Av (x) = Avo + Tvs−Tvo is obtained from the Apex conversion formula.

 When this equation is substituted into the above equation (9), Gv = Avo + Dv + Sv (100) −Sv + Tvs−Tvo (10)

On the other hand, since Av (x) = Avo in the trapezoid area, Gv = Avo + Dv + Sv (100) −Sv (11) from FIG. Therefore, based on this Gv value, the light emission time can be calculated or obtained from Step 7.

In the actual strobe 19, the G No. may be increased or decreased due to variations in the xenon tube or the main capacitor. For this reason, in the present embodiment, the emission time is increased or decreased by adding the Gv correction value GvSFT to the calculated Gv value,
Light is emitted at the desired light quantity. That is, a triangular area: Gv = Avo + Dv + Sv (100) -Sv + Tvs-Tvo trapezoidal area: Gv = Avo + Dv + Sv (100) -Sv As described above, the driving voltage of the sector is changed according to the change of the focal length. As a result, the time until the sector is opened can be constant regardless of the focal length. Therefore, since the exposure calculation at each focal length can be performed with the time until the opening being constant, the calculation processing can be simplified.

Further, in the above embodiment, since the brake time of the shutter motor is also changed in accordance with the focal length, the sector opening time can be adjusted efficiently.

Furthermore, since not only the opening time of the sector can be adjusted, but also the exposure value, the calculated opening time and the strobe guide number can be adjusted according to the focal length,
Very accurate exposure control is made possible.

The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the invention.

[Effects of the Invention] As described above in detail, according to the present invention, the time from the start of opening a sector to the opening aperture is made substantially constant according to the focal length information, so that exposure calculation can be simplified. An exposure control device for a variable focus camera can be provided.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention. FIG. 1 is a block diagram schematically showing a configuration of an exposure control device, FIG. 2 is a schematic diagram showing a camera to which the present invention is applied, and FIG. FIG. 4 is a diagram illustrating a shutter driving mechanism, FIG. 4 is a diagram illustrating a sector opening / closing operation, FIG. 5 is a diagram illustrating a telescopic aperture waveform, and FIG. FIG. 7 is a diagram schematically showing a shutter motor drive circuit, FIG. 8 is a timing chart for explaining shutter control, and FIG. 9 is a diagram for explaining a series of release operations. Timing chart shown in FIG. 10, FIG. 10 is a diagram showing the relationship between the charging voltage and light emission time during multiple light emission,
FIG. 11 is a timing chart showing the relationship between the light emission and the charging voltage during multiple light emission, FIG. 12 is a flowchart showing a series of release operations, and FIG.
FIG. 14 is a flowchart for explaining the shutter control operation, FIG. 14 is a flowchart for explaining the voltage setting and driving of the shutter motor, and FIG. 15 is a flowchart for explaining the operation at the time of checking the state of AEsw. ,
16 to 19 show a control flow relating to the strobe light. FIG. 16 is a flowchart for explaining an operation at the time of main light emission, and FIG. 17 is a view for explaining an operation at the time of pre-light emission. Flowchart, FIG. 18 is a flowchart for explaining an operation at the time of multiple light emission, FIG. 19 is a flowchart for explaining a light emitting operation at the time of multiple light emission, and FIG. 20 shows an example of a light emission time table. Figure, No.
FIG. 21 is a diagram for explaining the calculation of the second time in the triangular region of the aperture waveform, FIG. 22 is a diagram for explaining the calculation of the second time in the trapezoidal region, and FIG.
FIG. 24 is a diagram for explaining the adjustment process of the opening time in a case where the Mg delay time is longer than the design value, and FIG. 24 shows the calculation of the G No. value at the time of main emission in the triangular region of the opening waveform. FIG. 25 is a view for explaining the calculation of the G No. value during the main light emission in the same trapezoidal region. 32 ... sector (shutter blade), 41 ... control means, 42 ...
… Aperture restricting means when fully opened, 43 …… Focal length detecting means, 44
…… Zoom means, 46 …… Drive voltage calculation means, 47 …… E ² PR
OM.

Claims (1)

(57) [Claims] 1. A camera provided with a variable focus photographing lens having an opening / closing speed variable sector which serves both as an aperture and a shutter, wherein: a detecting means for detecting a focal length of the photographing lens; Opening restricting means for setting an opening F value regulated by the aperture when the sector is opened, setting means for setting the opening / closing speed of the sector, and the time from the start of opening the sector to the opening diameter. Control means for controlling the setting means in accordance with the set open F-number so as to be substantially constant.