JPH07114068A - Flash light control system - Google Patents

Abstract

PURPOSE:To provide a flash fight control system capable of obtaining an exposure suitable for a photographic scene under a camera by calculating an emitted light quantity, per a pulse and emitting light so as to consecutively output a high frequency pulse at the light quantity of the calculation, in the emission of flash light executed for a light exposure. CONSTITUTION:The emitted light quantity per a pulse is calculated from the total quantity of the flash light emitted during an exposing time, a control shutter speed in main light emission obtained based on output from a photometric circuit 3 and a light emission frequency previously set in the camera, the emitted light quantity per a pulse is monitored by a photodetector provided in a flashing device 9 and the start and completion of the emission of the light is controlled so that the emission of the light at a constant light quantity is executed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flash light control system which can be controlled by a camera in flash light emission at the time of slit exposure by controlling an exposure value according to a shooting scene.

[0002]

2. Description of the Related Art When flash photography is performed with flash light, if the shutter speed is equal to or faster than the flash synchronization shutter speed, the focal plane shutter does not fully open and the slit formed by the front and rear curtains has a film surface. (Slit exposure), but in such a case, even if the flash unit flashes at any time, only a part of the film surface will be exposed by the flash light and a uniform exposure photograph will be obtained. I can't shoot.

In order to solve the above problems, a continuous light emission type flash device in which a semiconductor switching element connected in series to a flash discharge tube is turned on / off at a minute time interval (Japanese Patent Laid-Open No. 61-98334). Gazette) and IGBT
(Insulated gate bipolar t
A flash device (Japanese Patent Application Laid-Open No. 64-17033) that continuously emits light using a transmitter has been proposed. When light emission is controlled by the flash device, slit exposure is performed even at a high shutter speed equal to or faster than the flash synchronized shutter speed. A flash device is disclosed which is capable of taking an unaffected uniform exposure photograph.

[0004]

The continuous tuning light emission of the flash device as described above does not control the light emission by calculating the light emission amount based on the automatic exposure calculation result, the subject distance, etc. It is difficult to obtain a drawing without failure in terms of exposure unless the user is a person, and it was difficult for a beginner to handle.

Therefore, the object of the present invention is to calculate the light emission intensity, the light emission amount or the dimming level during the main light emission from the result of exposure calculation, the subject distance, etc. in the flash light emission performed in the case of slit exposure. By controlling the light emission based on the calculation result, we provide a flash dimming system that can be controlled by the exposure according to the shooting scene (appropriate exposure considering the shooting effect peculiar to the shooting scene) even if shooting is left to the camera To do.

[0006]

The invention according to claim 1 is
A subject distance calculating means for calculating a subject distance, a photometric means capable of detecting the brightness by ambient light, a means for calculating the brightness which is obtained from the output of the photometric means and should be a reference for exposure control of the camera, Luminance luminous intensity calculation means for obtaining the luminance of the main subject irradiation by the flash from the luminance that should be the reference for the exposure control of the camera, and for obtaining the luminous intensity from the luminance of the main subject irradiation by the flash and the subject distance,
And a flat light emission control means for controlling light emission at a constant light intensity according to the output from the light emission intensity calculation means.

According to the second aspect of the present invention, the photometric means capable of detecting the brightness due to the ambient light, the light emission frequency output means for outputting the light emission frequency of the flash, and the total flash used during the exposure time. The amount of emitted light per pulse calculated from the amount of emitted light and the control shutter speed at the time of main light emission obtained from the output from the photometer and the emission frequency of the flash, and the amount of emitted light per pulse calculated from the means And a pulsed light emission control unit for controlling light emission in which a high-frequency pulse is continuously generated with a constant light amount according to the output.

Further, the invention according to claim 4 is for calculating a dimming level which is a reference for the control of the light emission start and the light emission stop for each pulse of pulse light emission in which a high frequency pulse is continuously emitted with a constant light quantity. A dimming level calculating means, a dimming means for monitoring whether or not the film exposure amount at the time of main light emission reaches the dimming level, and a high-frequency pulse with a constant light quantity according to the output from the dimming means. And pulse light emission control means for controlling light emission that is continuously performed.

[0009]

According to the first aspect of the invention, the luminous intensity at the time of main light emission is calculated from the output from the subject distance calculating means and the luminance of the main subject irradiation by the flash based on the luminance to be the reference for the exposure control of the camera. Then, the light emission with a constant light intensity (flat light emission) is controlled by the calculated light intensity.

According to the second aspect of the present invention, the control shutter at the time of main light emission is obtained based on the output from the photometric means capable of detecting the total amount of light emitted from the flash during the exposure time and the brightness of the stationary light. The amount of light emitted per pulse is calculated from the speed and the light emission frequency of the flash, and the constant amount of light emission (pulse light emission) for continuously performing high frequency pulses with the calculated amount of light is controlled.

According to the fourth aspect of the present invention, when the main light emission is performed up to the dimming level which is a reference for the control of the light emission start and the light emission stop for each pulse of the pulse light emission in which a high frequency pulse is continuously emitted with a constant light amount. Emission of a fixed amount of light (pulse emission) for continuously performing high-frequency flash emission is controlled according to the output from the light control means for monitoring whether or not film exposure has been performed.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, the focal plane shutter does not fully open at a high shutter speed equal to or higher than the flash synchronized shutter speed, and the slit formed by the front curtain and the rear curtain travels in front of the film surface (for slit exposure).
In this case, there are two types of flash light emission: light emission with a substantially constant light intensity from start to end (flat light emission) and light emission with continuous high-frequency mountain waveform (flash light waveform) from start to end (pulse light emission). It has a luminescent form.

Any one of the luminous intensity of the emitted light, the emitted light amount, and the dimming level (the level for monitoring the exposure amount on the film surface) is calculated from the exposure calculation result, the subject distance, and the like. Performing flash emission control based on the value will be referred to as high-speed synchronization control. Note that the luminous intensity is a value indicating the light intensity, and the light amount is a value obtained by integrating the light intensity over the light emission time.

A circuit block diagram (FIG. 1) of the entire camera system for performing the above control will be described. Reference numeral 1 is a focus detection circuit for performing focus detection. A focus lens drive circuit 2 drives a focus lens (not shown) to the in-focus position based on the focus detection result of 1. Reference numeral 3 denotes a photometric circuit for calculating the subject brightness, and the light receiving element of the photometric circuit is capable of multi-division photometry so that the main subject brightness and the background brightness can be calculated respectively. In addition,
The photometric circuit of this embodiment is a photometric circuit capable of determining whether or not a subject is backlit by a known method. Reference numeral 4 denotes a shutter control circuit that calculates the shutter speed based on the photometric value obtained in 3 and performs shutter control based on the calculated value. Reference numeral 5 denotes an aperture control circuit that calculates an aperture value based on the photometric value obtained in 3 and performs aperture control based on the calculated value. Reference numeral 6 is a circuit for charging the shutter and the diaphragm. Reference numeral 7 is a circuit for controlling film winding. Reference numeral 8 denotes a dimming circuit provided in the camera body for detecting the film exposure amount when the flash is emitted. A flash device 9 is externally attached to the camera. Reference numeral 10 is a film sensitivity detection circuit capable of detecting and setting film sensitivity. Reference numeral 11 is predetermined data of the lens, for example, focal length (FV), open aperture value (A
The lens ROM stores data such as V ₀ ) and the minimum aperture value (AV _MAX ).

In this embodiment, four implementations for performing the above-mentioned high-speed synchronization control (each of which is called a first mode to a fourth mode) are disclosed. FIG. 2 is a table showing an outline of the control performed in the above mode of the present invention. The light emission mode of the high-speed synchronization control is divided into the flat light emission and the pulse light emission, and the light emission is controlled by the flat light emission in the first mode and the pulse light emission in the second mode to the fourth mode.

In the first mode, flat light emission is performed, and the light control method performs test light emission for calculating the subject distance (DV) before the main light emission, and the subject distance, shutter speed, aperture value, and main subject by flash. Illumination brightness BV _F
(BV _F = BV _T + ΔEV _N
Called flash control brightness. Details of BV _T and ΔEV _N will be described later in the description of the first mode. ) And the luminous intensity is calculated, and the calculation result is sent to the flash to set the reference luminous intensity (the luminous intensity calculated above) of the monitor after the start of light emission, and the luminous intensity of the flash ( It is controlled by sending a signal to the IGBT provided in the flash light emission circuit (FIG. 15) by monitoring the light intensity) and stopping the light emission when the light intensity reaches the reference light intensity and starting the light emission when the light intensity becomes less than the light intensity. . The light receiving element of the photometric circuit for calculating the main subject brightness, the background brightness, and the main subject brightness of the test light emission is arranged in the pentaprism portion (not shown) of the camera. The above is the outline of the light emission mode and the light control method in the first mode.

In the second mode, pulsed light emission is performed, and the dimming method is test light emission before main light emission and subject distance (DV)
From the subject distance, aperture value, shutter speed, film sensitivity, emission frequency, and the correction amount (constant) for correcting the exposure amount of the main subject when the flash fires, and the light amount per pulse during the main flash. Is calculated, and the calculation result is sent from the camera to the flash and the reference light amount of the monitor (1 above) is calculated.
The light intensity per pulse is set, and the light emitting element located below the flash panel (not shown) monitors the amount of light emitted by the flash. The light emission is started and stopped, and the light emission start and light emission stop signals are transmitted to the IGBT provided in the flash light emission circuit. The above is the outline of the light emission mode and the dimming method in the second mode.

In the third mode, pulsed light emission is performed, and the dimming method is one pulse based on the correction amount (constant) for correcting the exposure amount of the main subject during flash light emission, the film sensitivity, the shutter speed, and the light emission frequency. A dimming level (SV-DA) corresponding to the amount of light emitted per hit is calculated. The light-receiving element for light adjustment is located at the bottom of the camera and monitors the light reflected from the film (exposure amount of film). It is transmitted to the IGBT provided in the circuit. The above is the outline of the light emission mode and the light control method in the third mode.

In the fourth mode, pulsed light emission is performed, and the dimming method calculates the subject distance (DV) based on the defocus amount output from the focus detection device, and the subject distance, aperture value, shutter speed, and film. The amount of light per pulse during main flash is calculated from the sensitivity, emission frequency, and the correction amount (constant) for correcting the exposure of the main subject during flash emission, and the calculation result is sent from the camera to the flash for monitoring. The reference light amount of (the appropriate light amount per pulse) is set, and the light emitting element arranged under the flash panel (not shown) monitors the emitted light amount with a flash. When the reference light amount is reached, the light emission is stopped and the The light emission is started and stopped a predetermined number of times based on the frequency, and the light emission start and light emission stop signals are provided to the flash light emitting circuit.
It is controlled by sending to the GBT. The above is the outline of the light emission mode and the light control method in the fourth mode. The details of the first to fourth modes will be described below for each mode.

<First Mode> FIG. 3 is a flowchart showing the sequence of the camera. When the camera power is supplied and the camera can be operated, the process proceeds to step S1. At step S1, the metering start switch (S1) is turned on.
It is determined whether or not, and if YES, the process proceeds to step S5. If NO in step S1, step S1 is repeated until the photometry start switch is turned ON in step S1. Distance measurement is performed in step S5, and step S1
Go to 0. In step S10, lens data is transmitted from the lens to the camera, and the process proceeds to step S15. The data transmitted in this step is the focal length (FV), the maximum aperture value (AV ₀ ), the minimum aperture value (AV _MAX ), and the like. In step S15, flash data is transmitted from the flash to the camera, and the flow advances to step S20 to perform photometry. Then, it progresses to step S25 and exposure calculation is performed. In this step, it is appropriate to control the light emission by the data transmitted from the lens to the camera, the data transmitted from the flash to the camera, or the high-speed synchronization control, the normal light emission control, or the non-light emission control based on the exposure calculation result. Decide what to do. The exposure calculation subroutine of this step will be described in detail later with reference to flowcharts (FIGS. 5 to 11).

Then, in step S30, the exposure calculation value obtained in step S25 and the emission control method (high-speed synchronization control, normal emission control, non-emission control) selected based on the exposure calculation value are flashed from the camera. Send to. In step S35, it is determined whether or not the release switch (S2) is ON. If NO in step S35, the process returns to step S1. YES in step S35
In the case of, it proceeds to step S45, it is determined whether or not the flash emission is requested, and in the case of YES, it proceeds to step S50. In step S50, the above step S
It is determined whether or not the light emission control selected in 25 is the high speed synchronization control. If YES, the process proceeds to step S55. In step S55, high-speed sync control described later is performed. The high-speed sync control in step S55 will be described in detail with reference to the subroutines of the flowcharts shown in FIGS. 29 to 32 and the time chart described later.
On the other hand, if NO in step S50, the normal light emission control is selected, and the process proceeds to step S60, where the mirror is raised and the aperture is narrowed down. Then, it progresses to step S65 and normal light emission control is performed. Moreover, NO in step S45.
In the case of No, the non-light emission control is selected, the process proceeds to step S70, and the mirror is raised and the aperture is narrowed down. Succeedingly, in a step S75, non-emission release control is performed. After step S55, step S65, and step S75, the process proceeds to step S80, and charging and film winding are performed. The above is the flowchart showing the sequence of the camera.

Here, the contents of data communication shown in each of the above-mentioned steps S15, S30 and S55 will be described with reference to the table shown in FIG. In step S15, data is transmitted from the flash to the camera. In this step, IV (a signal indicating the flash light amount), SSEN (a signal indicating that the flash device is capable of high-speed synchronization), LV _TEST (flash light intensity during test light emission), LV _MAX (maximum light intensity capable of light emission), and LV _MIN (minimum luminous intensity) is sent from the flash to the camera. In step S30, step S
The value calculated in step 25 is transmitted from the camera to the flash. The transmission data is DV in the first mode.
(Signal indicating subject distance), TV (signal indicating shirt speed), FV (signal indicating focal length), SV (signal indicating film sensitivity), AV (signal indicating aperture value), and NO.
TFIRE (a signal indicating whether or not the flash is emitted), FLATREQ (a signal indicating whether or not high-speed sync control is possible), and FLATTIME (a signal indicating a time for high-speed sync control). In step S55, LVC (a signal indicating the luminous intensity at the time of actual light emission) is transmitted from the camera to the flash. In the first mode, test light emission is performed to calculate the subject distance (DV), the luminous intensity LVC at the time of main light emission is calculated based on the subject distance, and the data (LVC) is transmitted from the camera to the flash. Has become. This is because the luminous intensity (LV) obtained in step S25 is the luminous intensity based on the subject distance (DV) calculated from the defocus amount output from the focus detection device, so focus detection can be performed at a short focal length. If done, it may be unreliable. Such a subject distance (D
V) For details on calculation, see Japanese Patent Application No. 57-228558.
Since this is a publicly known technique, the detailed description is omitted. In the first mode, an example has been shown in which test light emission is performed during the high-speed synchronization control in step S55, the subject distance is calculated, and the light emission intensity during main light emission is calculated based on the subject distance. In the exposure calculation, the test light emission is performed to calculate the subject distance, and the light emission intensity (LV) calculated from the subject distance may be used as the light emission intensity (LVC) during the main light emission, or the light intensity calculated in step S25 is directly The luminous intensity (LVC) at the time of main light emission may be used.

A flow chart (FIGS. 5 to 11) of the exposure calculation subroutine corresponding to the exposure mode (P, S, A, M) and the state of the subject (backlight, darkness, etc.) performed in step S25 will be described. . The P mode is
Program mode, A mode is aperture priority mode, S mode is shutter priority mode, M
The mode is a manual mode.

A flow chart of a subroutine of the above-mentioned exposure calculation at the time of automatic flash emission for backlighting and normal light emission and for forced emission will be described. Step S100, Step S
At 105, the following is done. In order to determine whether the shooting scene is backlit or forwardlit, the brightness difference ΔEV (ΔEV = ΔEV =) between the background brightness BV _A2 and the main subject brightness BV _S2
BV _A2 – BV _S2 ) is calculated and ΔEV is γEV or more (γ>
In the case of 0), it is determined that the subject is backlit and the background is overexposed and the main subject is underexposed. When ΔEV is less than γEV, it is determined that the subject is in forward lighting, The main subject is overexposed. In order to perform control that seems to be normal light (control so that the exposure of the main subject is overexposed to the background), at the time of normal light, the main subject brightness BV _S2 is αEV (correction amount for giving the feeling of normal light) Under, the aperture value AV _{C and the} shutter speed TV _C are found from a known program line based on the brightness BV _T (BV _T = BV _S2 + α) which is the reference for the exposure control of the camera. The aperture value A
V _{C and} shutter speed TV _C are values calculated based on the main subject reference (exposure control is performed with reference to the main subject brightness), and since flash light does not contribute to the background, the above B
V _T is the brightness that determines the exposure amount of the background. On the other hand, in order to perform a control that seems to be backlit (a control in which the background is overexposed and the main subject is underexposed), the main subject brightness BV _S2 is (ΔEV−β) EV (reverse backlight likeness) correction amount) becomes under, luminance BV _T as a reference for the exposure control of the camera _{(BV T = BV S2 + (} △ EV for
-Β)) based on aperture value AV _{C and} shutter speed T
V _C is obtained from a known program line. The aperture value AV _{C and the} shutter speed TV _C are values calculated on the basis of the background (the exposure control is performed on the basis of the background luminance), and since the flash light does not contribute to the background, the BV _T is the background. It is the brightness that determines the exposure amount of. Thus step S100, in step S105, it is determined whether a forward light or a backlight, and calculates the BV _T by the above method according to the determination, based on the aperture value AV and BV _T
C and shutter speed TV _C are calculated.

Subsequently, in step S110, it is determined whether or not the shutter speed TV _C is higher than the flash synchronizing shutter speed TV _X. In this step, it is determined whether the shutter speed is a slit-like shutter speed (shutter speed requiring high-speed synchronization control). If YES in step S110, the process proceeds to step S115. On the other hand, in step S110, N
In the case of O, the process proceeds to step S111 and shifts to the flowchart of the normal light emission subroutine. Step S1
In 15 and step S120, the following control is performed. Luminance BV that is the reference for the exposure control of the camera
The brightness BV _F (BV _F = BV _T + ΔEV _N ) of the main subject irradiation by the flash is calculated from _T and the exposure correction amount ΔEV _N (constant) that contributes to the exposure of the main subject during flash emission. The ΔEV _N is a constant determined according to the photographing condition (backlight, normal light, darkness, etc.). Then, from the BV _F and the subject distance DV, the luminous intensity LV (LV = BV _F +
The luminous intensity that can be stopped even by DV will be hereinafter referred to as the luminous intensity. The subject distance DV here is a value calculated from the defocus amount from the focus detection device described above.

The routine of steps S125 to S135 is a routine to be executed when it is judged that the control by the high speed synchro control is suitable because the control can be performed by the light intensity calculated in step S120. Specifically, in step S125, it is determined whether or not the emission light intensity LV is higher than the flash controllable minimum light intensity LV _MIN . If YES in step S125, step S125
Proceeding to 130, it is judged if the LV is higher than the maximum flash controllable luminous intensity LV _MAX . On the other hand, if NO in step S125, the routine proceeds to block 1. Then, if YES in step S130, the flow proceeds to step S135, and the high speed sync flag is set. If NO in step S130 (control is impossible with the above-described light emission intensity LV), the process proceeds to step S140. Since the routines of steps S140 to S150 cannot be controlled by the luminous intensity calculated in step S120,
A routine for re-calculating a smaller BV _T than the luminance BV _T as a reference for the exposure control of the camera calculated previously in step S100. Specifically, in step S140, it is determined whether or not the brightness BV _{T that} is the reference for the exposure control of the camera is higher than the main subject brightness BV _S2 . Step S1
If YES in step 40, the process proceeds to step S145, and B
Recalculate V _T. The operation performed in step S145 is calculated by BV _T = BV _S2 + α−δ during forward light, and is calculated by BV _T = BV _S2 + (ΔEV−β) −δ during backlight. In step S150, the aperture value AV _{C and the} shutter speed TV _C are obtained from a known program line based on the recalculated BV _T.
Then, the process proceeds to step S110 again, and the same processing as the flow described above is performed. N in step S140
When it is O (the main subject brightness BV _S2 is larger than the brightness BV _T which is the reference for the exposure control of the camera), the routine proceeds to block 1.

Next, the block 1 shown in FIG. 6 will be described. N in step S125 and step S140
If O, go to block 1. The routine of steps S160 to S175 performed in block 1 is a routine to proceed when high-speed synchronization control is impossible,
This routine is executed when it is appropriate to perform normal light emission control or non-light emission control. In step S160, the shutter speed TV _C is synchronized with the synchronized shutter speed T.
After shifting to V _X , the aperture value A is changed by the number of shifts.
An aperture value AV _C obtained by shifting V _C is calculated. Succeedingly, in a step S165, it is determined whether or not AV _C is equal to or less than AV _MAX . If YES in step S165, step S165
In step 170, the shutter speed TV _C is shifted to TV _X , and the process proceeds to the normal light emission amount calculation subroutine in step S175. On the other hand, if NO in step S165, the process proceeds to step S180, and it is determined whether or not the forced light emission is performed. If YES in step S180, step S180
Proceeding to 135, the high speed sync flag is set. On the other hand, if NO in step S180, step S1
Proceeding to 85, the stationary light flag is set. The above is the description of the subroutine for the exposure calculation at the time of the flash automatic light emission at the time of the backlight and the normal light and the forced light emission.

Next, the flowchart of the normal light emission subroutine of FIG. 7 will be described.

The above-mentioned FIG. 7 is shown as a subroutine for normal light emission in the flow chart FIG. 6 for automatic flash emission for backlighting and forward illumination and for forced emission, but this flowchart is for automatic flash emission for backlighting and forward illumination. Further, it is not limited to the normal light emission subroutine at the time of forced light emission, but is applicable according to the normal light emission release control of the previous step S65 and the normal light emission control subroutine of FIGS. 9 to 11, 23 and 26 described later. Is. Steps S200 to S215 are a routine to proceed when control is possible with the light amount calculated in step S200.
Specifically, the exposure time is calculated from the aperture value AV _C , the subject distance DV, the exposure correction amount ΔEV _N (constant) that contributes to the exposure of the main subject at the time of flash emission, and the film sensitivity SV, which are calculated in step S200. Total amount of light emitted inside IV
(IV = AV _C + DV + ΔEV _N −SV) is calculated.
Succeedingly, in a step S205, it is determined whether or not the daytime synchronization is performed. If YES, the process proceeds to step S210, and the above IV is the flash control maximum guide number IV.
_It is determined whether it is smaller than _MAX . On the other hand, step S
If NO in 205, the process proceeds to step S215. If YES in step S210, step S2
Proceeding to 15, the high speed sync flag is reset. If NO in step S210, step S2
Go to 25.

The routine of step S225~ step S245 is not recalculated BV _T, a routine proceeds when performing recalculation of IV by changing the aperture value AV _C. Specifically, in step S225, it is determined whether the aperture value AV _C is equal to the open aperture value AV ₀ . If YES, the process advances to step S230 to determine whether the shutter speed TV _C is not equal to the flash synchronized shutter speed TV _X. If YES, step S2
In step 35, the shift amount is calculated by shifting by the amount corresponding to the smaller stage number difference of _MIN {AV _C -AV ₀ , TV _C -TV _X }. Then, the process proceeds to step S240,
The AV _C shifted by the shift amount corresponding to the step number difference obtained in step S235 is calculated. Succeedingly, in a step S245, the TV _C shifted by the shift amount corresponding to the difference in the number of stages obtained in the above step S235.
To calculate. If NO in step S230, the process proceeds to step S250.

The routine from step S250 to step S270 is executed by the flash synchronizing shutter speeds TV _X and TV _C.
Are the same, so as in step S235, the TV
_Since the shift amount obtained by shifting _C cannot be calculated, the shift amounts of BV _T and main subject brightness BV _{S 2} are calculated. Specifically, in step S250, it is determined whether BV _T is larger than the main subject brightness BV _S2 . If YES in step S250, step S250
Proceeding to step 255, a shift amount obtained by shifting the shift amount by the amount corresponding to the smaller one of _MIN {AV _C -AV ₀ , BV _T -BV _S2 } is calculated. Subsequently, the process proceeds to step S260, and the BV _T subtracted by the shift amount obtained in step S255 is recalculated. Succeedingly, in a step S265, an AV _C shifted by an amount of shift corresponding to the step number difference obtained in the step S255 is calculated. continue,
In step S270, it is determined whether or not (BV _S2 −BV _T )> − 1. If YES, step S20 again
The process proceeds to 0 and the same processing as described above is performed. If NO in step S225 or NO in step S250, the process proceeds to the routine of block 2 in FIG.

In block 2, it is determined in step S280 whether forced light emission is performed. If YES, the process advances to step S285, and the high speed sync flag is reset. On the other hand, if NO in step S280, the flow advances to step S295 to set the stationary light flag. The above is the description of the flowchart of the normal light emission subroutine.

Next, the flow chart of the subroutine for exposure calculation at the time of automatic light emission in P-dark in FIG. 9 will be described. Although the routine for calculating the aperture value AV _{C and the} shutter speed TV _C is not shown in this flowchart, the aperture value AV _{C and the} shutter speed TV _C are determined based on the brightness of the main subject.

The routine of steps S300 to S325 is executed when the camera shake shutter speed TV _H (1 / focal length) is larger than the flash synchronizing speed TV _X and the shutter speed TV _C is smaller than the camera shake shutter speed TV _H. Therefore, when TV _C is smaller than TV _H and LV is within the controllable light intensity range, high-speed sync control is possible, so there is a possibility that camera shake will occur, but this is a routine to proceed when high-speed sync control is selected. is there.
Specifically, in step S300, it is determined whether or not the camera shake shutter speed TV _H (1 / focal length) is higher than the flash synchronized shutter speed TV _X. If YES, the process advances to step S305, and the camera shake shutter speed T
It is determined whether V _H is greater than the control shutter speed TV _C. If NO in step S300, the process proceeds to block A. If YES in step S305, step S305
In step 310, aperture value AV _C and camera shake shutter speed T
The brightness BV _F (BV _F = AV _C + TV _H -SV) of the main subject irradiation by the flash is calculated from V _H and the film sensitivity SV. On the other hand, in the case of NO in step S305, it is determined that the non-light emission control is suitable, and the stationary light flag is set. In step S315, the luminous intensity LV (LV = BV _F + DV) is calculated from the BV _F and the subject distance DV.
The subject distance DV here is a value calculated from the defocus amount from the focus detection device described above. Succeedingly, in a step S320, it is determined whether or not the light intensity LV is within a flash controllable range. Step S3
If YES in step 20, the process proceeds to step S325, and the high speed sync flag is set. N in step S320
In the case of O, the process proceeds to step S335.

The routine of steps S335 to S340 is a routine to be executed when the light does not reach the main subject without the normal light emission and when it is judged that the normal light emission is appropriate because TV _C is smaller than TV _X and the normal light emission is possible. Is. Specifically, in step S335, the flash synchronized shutter speed TV _X is set to the control shutter speed T.
It is determined whether or not it is V _C or more. If YES, the process proceeds to step S340, the high-speed sync flag is reset, and the same control as that in the flowchart of the normal light emission subroutine (FIGS. 7 and 8) is performed. N in step S335
In the case of O, the process proceeds to step S350, in which the normal light emission control cannot be performed because TV _C is larger than TV _X, and it is determined that the non-light emission control is appropriate, so the steady light flag is set.

If NO in step S300, the process proceeds to block A. The block A (FIG. 10) will be described. In the routines of steps S355 to S360, since TV _X is larger than TV _{H and} TV _C is smaller than TV _H , camera shake may occur. Since TV _C is smaller than TV _X , normal light emission is possible. Is a routine to proceed when it is determined that normal light emission is appropriate. Specifically, in step S355, the camera shake shutter speed TV
_It is determined whether _H is greater than the control shutter speed TV _C. In the case of YES, the process proceeds to step S360, the high speed synchronization flag is reset, and the same control as the flowchart (FIGS. 7 and 8) of the normal light emission subroutine is performed. If NO, the process proceeds to step S370, and since TV _C is larger than TV _H and there is no fear of camera shake, it is determined that non-light emission control is appropriate and the steady light flag is set. The above is the description of the routine of block A.

A flowchart of the exposure calculation subroutine of the aperture priority (A mode), shutter priority (S mode) and manual mode (M mode) shown in FIG. 11 will be described. Although the routine for calculating the aperture value AV _{C and the} shutter speed TV _C is not shown in this flowchart, the aperture value AV _{C and the} shutter speed T are set as in steps S100 to S105 described above.
V _C is determined.

When aperture priority, shutter priority, and manual mode are selected and the flash is turned on, step S
Proceed to 400. The routine of steps S400 to S415 is a routine to be executed when it is determined that the high-speed sync control is suitable because TV _X is larger than TV _C. Specifically, in step S400, it is determined whether the shutter speed TV _C is higher than the flash synchronized shutter speed TV _X. This step S400 determines whether or not the TV _C has a shutter speed that requires high-speed synchronization. If YES in this step, step S
Proceed to 405. In step S405, the brightness BV _F of the main subject irradiation by the flash is calculated as in step S115 described above. Then, the process proceeds to step S410, the BV _F and the object distance DV from intensity LV (LV
= BV _F + DV) is calculated. The subject distance DV here is a value calculated from the defocus amount from the focus detection device described above. In step S415, the high speed sync flag is set. Although this flowchart does not judge whether or not LV _MIN <LV <LV _MAX , these judgments may be made, and LV <LV
_{When MIN} or LV _MAX <LV, the control luminous intensity LV may be replaced with LV _MIN or LV _MAX , respectively, for control. If NO in step S400, the TV
_{Since X} is larger than TV _C, normal light emission is possible, so it is determined that normal light emission control is appropriate, so the flow proceeds to step S430, the high-speed sync flag is reset, and the above-described normal light emission control flowchart (FIG. 7, FIG. Proceed to 8). The above is the flowchart of the exposure calculation subroutine in the A, S, and M modes.

Next, the flow chart of the subroutine of the high speed synchro control in the first mode executed in step S55 will be described with reference to FIG. In the first mode, the luminous intensity LVC at the time of main light emission is calculated based on the subject distance (DV) obtained by performing the test light emission as described above. In step S800, test light emission is performed, the process proceeds to step S805, the main subject brightness at the time of test light emission is calculated, and the process proceeds to step S810.
Calculate V. Here, an arithmetic expression for calculating a subject distance (DV) by test light emission will be described. First, the symbols appearing in the calculation formula for calculating the subject distance will be described. BV1 is the brightness of the main subject due to the constant light, BV2 is the brightness of the main subject during test light emission, and LV _TEST is the luminous intensity during test light emission. If the luminance change of the main subject luminance caused by the test light emission is defined as BV3 (BV3 = BV2-BV1), the subject distance (DV) is calculated from the following equation.

[0040] DV = LV _TEST over BV1 over log _{2 (2} ^BV3-1) In step S815, light intensity LV (LV = BV during the light emission from the luminance BV _F of the main subject illuminated by the flash and the subject distance (DV) It is calculated by _F + DV).
In step S820, the mirror up and narrowing down are started, and the light emission intensity (LVC) at the time of main light emission performed in step S815 before the traveling of the shutter is transmitted from the camera to the flash (step S825). Step S8
At 30, the shutter travel and main light emission are performed. The above is the subroutine of the high-speed sync control in the first mode.

Here, the automatic selection control of light emission control (automatic selection of high-speed synchro control light emission, normal light emission, and constant light photography) in the above-described flowcharts shown in FIGS. The control shutter speed at the time of main light emission will be shown. The effective distance that the flash light reaches in normal light emission is longer than the effective distance that the flash light reaches because of the high-speed synchronization control.
_C is the shutter speed calculated by the exposure calculation in step S25, TV _X is the flash synchronizing shutter speed, and TV _H is the camera shake shutter speed. Further, when TV _C <TV _{H in} the dark, there is a possibility of camera shake, which can be prevented by performing normal light emission (flash light emission).

(1) Program automatic light emission in the dark (when the flash is automatically emitted due to the dark subject in P mode) [1] When TV _H <TV _X and TV _H <TV _C : During main light emission Control shutter speed TV _C performs high-speed sync control.

[2] When TV _H <TV _X and TV _C <TV _H : Normal light emission is performed at the control shutter speed TV _X during main light emission.

[3] When TV _X <TV _H and TV _C <TV _X and the main subject is within the high-speed synchro effective range: The high-speed synchro control is performed at the control shutter speed TV _H during main light emission.

[4] When TV _X <TV _H and TV _C <TV _H and the main subject is outside the effective range of high-speed synchronization: Normal light emission is performed at the control shutter speed TV _X during main light emission.

[5] When TV _X <TV _H and TV _C <TV _H and the main subject is within the high-speed synchro effective distance: The high-speed synchro control is performed with the control shutter speed TV _H during main light emission.

[6] When TV _X <TV _C and TV _C <TV _H and the main subject is outside the effective range of high-speed synchronization: Non-emission control is performed at the control shutter speed TV _C. Alternatively, when the main subject brightness is −2 EV or higher, high-speed sync control is performed.

(2) Program backlight automatic emission (when flash is automatically emitted when backlight is determined in P mode) [7] When TV _C <TV _X : Control shutter speed TV _C during main emission To emit light normally.

[8] TV _X <TV _C , when the main subject is within the effective range of high-speed synchronization: Control shutter speed T during main flash
High-speed sync control is performed with V _C. [9] TV _X <TV _C , if the main subject is outside the high-speed sync effective distance but within the normal flash effective distance, and if the control shutter speed during main flash is set to TV _X and the exposure is controlled properly: Main flash performing a normal light-emitting in the control shutter speed TV _X of the time.

[10] TV _X <TV _C , when the main subject is outside the high-speed synchronization effective distance but within the normal light-emission effective distance, and when the control shutter speed during main light emission is set to TV _X , overexposure occurs : Non-light emission control is performed with the control shutter speed TV _C during main light emission.

[11] TV _X <TV _C , when the main subject is outside the effective distance for high-speed synchronization and outside the effective distance for normal light emission: Non-emission control is performed at the control shutter speed TV _C during main light emission.

(3) Program forced flash (when the photographer forcibly flashes the flash in P mode) [12] When TV _C ≤ TV _X : Normal flash is performed at the control shutter speed TV _C during main flash .

[13] TV _X <TV _C , when the main subject is within the effective range of high-speed synchronization: Control shutter speed T during main flash
High-speed sync control is performed with V _C.

[0054] _{[14] TV X <TV C} , TV controls shutter speed during the emission main subject at a high speed synchro effective distance outside _X
When the proper exposure is obtained when controlled by: The normal light emission is performed at the control shutter speed TV _X during the main light emission.

[15] When TV _X <TV _C , the main subject is out of the effective range for high-speed synchronization, and the control shutter speed during main flash is TV _X to control overexposure: If: Main flash Control of shutter speed Perform high-speed synchronization control with TV _C.

(4) Forced flash in aperture priority mode (when the photographer forcibly fires the flash in A mode) [16] When TV _C ≤ TV _X Normal flash at control shutter speed TV _C during main flash I do.

[17] When TV _X ≤TV _C and the main subject is within the high-speed synchro effective distance: The high-speed synchro control is performed at the control shutter speed TV _C during main light emission.

[18] When TV _X ≤TV _C and the main subject is outside the effective range of high-speed synchronization High-speed synchronization control is performed at the control shutter speed TV _C during main light emission.

Alternatively, the control shutter speed TV _X is turned off.

(5) Forced flash in shutter priority and manual mode (when the photographer forcibly flashes in S mode and M mode) [19] When TV _C ≤ TV _X Control shutter speed during main flash Emit normal light on TV _C.

[20] When TV _X ≦ TV _C High speed synchronization control is performed with the control shutter speed TV _C at the time of main light emission.

Further, a high-speed synchro switch or the like may be provided, and when the switch is operated, for example, when TV _C <TV _X , the high-speed synchro control may be forcibly performed.

FIG. 12 is a diagram showing the external appearance (display section and operation section) of the flash device. Reference numeral 10 is a main switch for supplying power to the flash unit. Reference numeral 11 denotes a display section for displaying whether the current mode is high-speed synchronization or normal light emission, and can be manually selected by a MODE key for mode switching of 12. Reference numeral 13 is a display unit showing the maximum flash light reach distance and the minimum flash light reach distance. Note that the left diagram of FIG. 12 is a display example during normal light emission, and the right diagram is a display example during high speed synchronization.

Next, the connection diagram showing the connection between the camera and the flash shown in FIG. 13 will be described. As described above, between the camera and the flash, the data communication shown in Table 2 shown in FIG. 4 and the control signals such as the start and stop of light emission from the camera are transmitted to the flash. The contact F1 is a contact for outputting a flash emission start signal from the camera to the flash. The contact F2 is a contact for performing serial communication of data (SO) sent from the flash to the camera and data (SI) sent from the camera to the flash. The serial communication data (SO) and data (SI) sent from the contact F2 are shown in FIG. The contact F3 is a contact for sending a clock for outputting a timing signal of the data sent from the contact F2 from the camera to the flash. The signals input / output from the contacts F2 and F3 are connected to the flash via I / O. Data communication between the camera and the flash is performed using the contacts as described above.

The serial communication contents (SO, S
I) will be described. In addition, what is described in FIG.
Only the data particularly necessary for the high-speed sync control of the present invention will be selected and described, and the known data necessary for normal light emission will be omitted.

The data (SO) transmitted from the flash to the camera will be described. SSEN is a signal indicating that the camera is capable of high speed synchronization. LV _MAX is a signal indicating the maximum luminous intensity of the flash, LV _MIN is a signal indicating the minimum luminous intensity of the flash, LV _TEST
Is a signal indicating the luminous intensity during test light emission. IV _MAX is a signal indicating the maximum guide number that the flash can emit, and IV _MIN is a signal indicating the minimum guide number that the flash can emit. LV _T is a signal indicating the luminous intensity at the time of test light emission in the second mode (luminosity after t seconds after the test light emission).

Next, the data (SI) sent from the camera to the flash will be described. DV is a signal indicating information on the subject distance. TV is a shutter speed, FV is a focal length, SV is a film sensitivity, and AV is a signal indicating an aperture value. FLATREQ is a high-speed sync request signal indicating that the camera requests the flash for high-speed sync control. FLATTIME is a signal indicating the time for which high-speed sync control is performed. IVC is the amount of light emitted during main light emission, and LVC is the light emission intensity during main light emission. The above data communication is performed between the camera and the flash.

Here, the calculation of FLATTIME will be described. The calculation of FLATTIME is calculated by the following formula.

FLATTIME = shutter speed + curtain speed + α Incidentally, the curtain speed is the speed at which the shutter curtain of the focal plane shutter travels on the photographing screen, and α is FL in the above equation.
The reason for adding to ATTIME is to control light emission for a longer time than the time for true high-speed synchronization control in consideration of control error.

The configuration and operation of the flash light emitting circuit of FIG. 15 and the flash control circuit of FIG. 16 will be described below. The flash light emission circuit and the flash control circuit are circuits that can be adapted to light emission during high-speed synchronization control in all modes of the first mode to fourth mode and normal light emission.

The structure of the flash light emitting circuit of FIG. 15 will be described. In the figure, SW1 is a main switch of the flash device, and the flash device is turned on and off.
To control. When SW1-1 is turned on, a power of about 6 V is supplied to the DC-DC converter. SW1-2 is SW1
It is designed to open and close in conjunction with the opening and closing of -1. 12
Is a DC-DC converter provided to boost the voltage, and the main capacitor (C1) is charged.
Xe is a flash discharge tube that is powered by the main capacitor (C1) and emits light. Turn on / off light emission in this discharge path
An IGBT for F is provided. The collector terminal of the transistor (TR1) is connected to the base terminal of the IGBT, and the IGBT control signal is input to the base terminal from the flash control circuit. Transistor (T
When the R1) turns off, 12 is applied to the base terminal of the IGBT.
The voltage of V is applied and the IGBT is turned on. Conversely, when the transistor (TR1) turns on, the IGBT turns off. Also, the capacitor (C2), transformer (T), and IG
BT constitutes a trigger circuit. Capacitor (C
2) is a capacitor charged to excite the flash discharge tube (Xe), and is charged with a potential equal to that of the main capacitor (C1). Here, when the IGBT is turned on, the electric charge charged in the capacitor (C2) is discharged via the transformer TR, the voltage boosted by the transformer TR is applied to Xe, and Xe starts emitting light. Note that C3 is a capacitor provided to apply a double pressure to the flash discharge tube (Xe) to facilitate light emission. The VM terminal has resistors R1 and R2 connected in parallel with the main capacitor C1 for monitoring the voltage charged in the main capacitor C1.
It is located at the position where it is pulled out from between. The above is the configuration of the flash light emitting circuit.

Next, the operation of the flash light emitting circuit will be described. When the main switch SW1-1 of the flash is turned on, SW1-2 is also turned on in conjunction with it. Then, the power supply voltage of 6V is boosted by the DC-DC converter, and the main capacitor (C1) is charged with the voltage of 300V through the diode (D1). Here, the capacitor (C2) forming a part of the trigger circuit and the capacitor (C3) provided for applying a double voltage to the flash discharge tube (Xe) are also charged with the voltage of 300V. afterwards,
IGBT control signal on the base of transistor (TR1)
When L "is input, the transistor (TR1) is turned off and 12 V is supplied to the base of the IGBT. As a result, the IGBT is turned on, and at the same time, the trigger circuit is activated and the flash discharge tube Xe emits light. During light emission, the IGBT control signal "H" is applied to the base of the transistor (TR1).
When is input, the IGBT is turned off and the light emission is interrupted. Then, again on the base of the transistor (TR1)
When "L" is input, light is emitted again. By repeating this operation at high frequency, that is, by continuously inputting "H" and "L" to the base of the transistor (TR1), light emission of approximately constant light intensity is achieved. Done.

The structure of the flash light emitting circuit of FIG. 16 will be described. In the figure, Xe is the above-mentioned flash discharge tube. Reference numeral 13 is a light receiving element arranged below the flash panel for receiving the light projected from the flash discharge tube (Xe). This light receiving element is provided for monitoring the flash light intensity and outputting a current according to the flash light intensity. The current is input to OP1.
OP1 is an operational amplifier, and the output current from OP1 is converted into a voltage logarithmically compressed by the diodes D2 and D3 and output. The D / A adder circuit is a circuit for raising the output voltage of OP1 for the purpose of adjusting the luminous intensity, and is provided for adjusting the luminous intensity. TR2 is a transistor provided for converting a logarithmically compressed output voltage output from the operational amplifier (OP1) into a logarithmically expanded current. Similar to the transistor (TR2), D4 is provided to convert the logarithmically compressed output voltage output from the operational amplifier (OP1) into a logarithmically expanded current. The transistor (TR3) and the FET are turned on by a signal from an F / PMODE described later.
3) and the FET are turned on and off to operate as a switch for controlling whether or not the resistor (R3) or the capacitor (C4) is electrically connected. The comparator (COMP) is provided to compare the potential input to the non-inverting input terminal generated when a current flows through the resistor (R3) with the constant potential connected to the inverting input terminal of the comparator (COMP). Here, the reason why the current is caused to flow through the resistor (R3) instead of through the capacitor (C4) is that light emission is controlled at a substantially constant luminous intensity in the first mode. That is, the current (corresponding to the output from the light receiving element) flowing through the resistor (R3) corresponds to the intensity of light (luminous intensity), and the control as described below is performed by comparing with the comparator (COMP). This is because. It is because when the current flowing through the resistor (R3) becomes a certain value (constant light intensity) or less, the comparator (COMP) turns the IGB
The T control signal is set to "H" to cause the flash to emit light, and when the current flowing through the resistor R3 becomes equal to or higher than a constant current (constant light intensity), the IGBT control signal is set to "L" to stop the flash emission. Since this operation is repeated at high speed, the IGBT is turned on and off at a high frequency and can be controlled with a substantially constant light intensity. On the other hand, the reason why the current is passed through the capacitor (C4) in the second mode to the fourth mode of the normal light emission and the high-speed synchronization control described later is that the light emission controls the light emission. That is, the electric charge (corresponding to the output from the light receiving element) accumulated in the capacitor (C4) corresponds to the light amount, and the potential difference generated in the capacitor (C4) and the reference voltage are compared by the comparator (COMP). This is because the following control is performed. When the flash emission starts and the electric charge accumulated in the capacitor (C4) becomes a certain value or more, the comparator (COMP) is inverted and outputs "L". The output makes the IGBT control signal "L" to stop the flash emission. By repeating this operation at high speed, it is possible to achieve pulsed light emission with a continuous light emission form. The transistor (TR4) to which the signal output from FLGATE is input during normal light emission functions as a switch for discharging the electric charge accumulated in the capacitor (C4). Also, C of the flash control circuit
The PU has the following contacts. F / PM
The ODE output is an output terminal for switching between flat light emission and pulsed light emission, "L" is output in the case of flat light emission in the first mode, and "H" in the case of pulsed light emission.
Is output. SSMODE is a terminal for switching between flat light emission and pulsed light emission. GN terminal is the above D / A
This is the output terminal to the adder circuit. FLGATE is a gate terminal for switching between enabling and disabling of integration into C4 and receiving a light emission stop signal from the FLSTP terminal. TRIGON is a terminal for starting pulse light emission, and TRIGOFF is a terminal for forcibly stopping pulse light emission. VM is a terminal for monitoring the voltage corresponding to the electric charge charged in the main capacitor (C1) described in FIG. X is a terminal for inputting a timing signal for starting a series of flat light emission or pulsed light emission, and the signal is switched from "H" to "L" immediately before the shutter curtain opens. SO and SI are terminals for inputting / outputting SO data and SI data signals described in FIG. SCK is a terminal for inputting a clock transmitted from the camera.

Next, an outline of the configuration of the logic circuit shown in the flash control circuit will be described based on the light emitting operation during the high-speed sync control in the first mode. In the first mode, NA
Since "L" is input to the ND2 from the F / PMODE terminal, the NAND2 always outputs "H" to the AND1 regardless of the output from the OR3. That is, NAND
2 is a configuration for preventing AND2 from being influenced by signals of F2, F3, FLSTP, and FLGATE.
Therefore, "H" is always input to AND1 from NAND2. Therefore, the same output signal as the output from TRIGOFF is input to the reset terminal of the flip-flop. The output from TRIGON is input to the set terminal of the flip-flop. Therefore, the flip-flop is controlled only by the light emission signal TRIGON and the light emission stop signal TRIGOFF from the CPU. On the other hand, from "F / PMODE"
Since the L ″ signal is also input to OR4, the output signal from COMP is directly input to AND2.
R4 is a configuration for giving the output from COMP to AND2 as it is. Also, during flash emission (that is, after the TRIGON is output, TRIGOF
Until F is output)
Since H ″ is input to AND2, the IGBT control signal corresponds to the output from COMP. Therefore, the high-frequency pulse train output from COMP is the IGBT.
It becomes a T control signal and becomes the transistor (TR1) of the above-mentioned FIG.
Entered in. The above is an outline of the configuration of the flash control circuit and its logic circuit.

The operation of the flash control circuit will be described. In the case of the first mode, from the F / PMODE, "
"L" is output and "L" is input to OR4. Before the flash emission, the output of the comparator (COMP) is "
Since it is "H" and the output of the flip-flop is also "H",
The IGBT control signal becomes "H". The output of the flip-flop during flash emission is always "H", and the output is input to AND2. Therefore, the comparator (CO
When the output from MP) is "H", the IGBT control signal outputs "H", and when it is "L", the IGBT control signal outputs "L". Doing this repetition at high frequency, that is, to the base of the transistor (TR1)
By continuously repeating the input of H "and" L ", light emission with a substantially constant light intensity is performed.
For the latter), since the F / PMODE outputs "L", the output of the NAND2 is always "H". Since the output is input to AND1, the flip-flop is reset when "L" is input from TRIGOFF. As a result, "L" is output from the flip-flop, the output to the IGBT is always "L", and light emission is stopped. In synchronization with this, FLGATE becomes "H" and the transistor (TR4) is turned on, so that the operation of the comparator is stopped. As described above, the flash control circuit is provided to input the data (SO, SI) from the camera, control the flash intensity, and control the output of the IGBT control signal.

Next, a flow chart showing the flash sequence will be described with reference to FIGS. Step S
At 500, an initial reset of the CPU provided in the flash is done. In this step, zoom, display, communication data, etc. are reset and initial values are set.
Succeedingly, in a step S505, the interrupt is permitted. An interrupt occurs when data is transmitted from the flash to the camera in step S15 (W)
In step S30, the data is transmitted from the camera to the flash (R) and the release (REL) is performed. Succeedingly, in a step S510, charging start, stop, charge completion display and the like of the electric charge required for flash emission to the capacitor are performed. Succeedingly, in a step S515, the irradiation angle of the flash panel is changed based on the focal length data (FV) sent from the camera. Succeedingly, in a step S520, a setting change as to which of high-speed sync control and normal light emission is to be selected is made according to a setting made by a key input of the flash device. Succeedingly, in a step S525, a display corresponding to the key processing is performed. continue,
In step S530, it is determined whether the flash operation has not been performed for a certain period of time. In this step, if the flash has not been operated for a certain time,
It is provided for the purpose of automatically turning off the power (auto power off) after a lapse of a certain period of time to avoid wasting the power.
If YES, the process proceeds to step S535, and auto power off is performed.

A flowchart of the interrupt process after the interrupt permission in step S505 will be described with reference to FIG. When an interrupt occurs in step S505, step S54
At 0, it is judged which of the R, W and REL has been selected. In the case of R, the process proceeds to step S545, FLATREQ, test light emission, LVC, FLATT
Data such as IME, that is, SI data shown in FIG. 14, is transmitted from the flash to the camera. In the case of W, the process proceeds to step _{S550, LV MAX, LV MIN,} LV TE ST, F
Data such as DC, that is, SO data shown in FIG. 14, is input to the camera from the flash. In the case of REL, the process proceeds to step S555 and release processing is performed.

The release processing subroutine of step S555 will be described with reference to FIG. Step S56
At 0, it is determined whether or not the camera is requesting high-speed sync control. If YES, step S565.
Then, it is determined whether or not the test light emission signal is input. The test emission signal means that the X terminal of the contact F1 is "
It is determined that the value is "L" or the test light emission flag is set. If YES, step S5
Proceeding to 70, test light emission is performed. Also, step S
If NO in 565, YE in step S565.
Step S565 is repeated until S is reached. Note that steps S565 to S570 are processes performed in the first mode and the second mode in which test light emission is performed, and this routine is not necessary in the third mode and the fourth mode. Succeedingly, in a step S575, it is determined whether or not dimming is possible. In this step, the flash light is monitored and determined to determine whether the flash can actually be controlled by the LVC. Then, step S
Proceeding to 580, FDC processing is performed. The FDC process is a process of displaying a charge completion message on the camera and displaying a flash start signal on the flash. Succeedingly, in a step S585, it is determined whether or not a light emission start signal is input. If YES, step S590
Then, the high speed sync control is performed. If NO in step S585, Y in step S585.
Step S585 is repeated until ES is reached.
The above steps S560 to S590 are the release process when the high-speed sync control is performed.

If NO in step S560, the flow advances to step S595 to determine whether a light emission start signal has been input. If YES, step S
Proceeding to 600, normal light emission control is performed. If NO in step S595, step S595 is repeated until YES. Then, step S6
The routine proceeds to 05, where it is determined whether or not dimming is possible. This is a step for determining whether or not the proper exposure is performed by the normal light emission performed in step S600. Then, it progresses to step S610 and FDC processing is performed.
The above steps S595 to S610 are the release process at the time of normal light emission.

The flow chart of the subroutine of the FDC processing will be described separately for the high speed synchronization and the normal light emission. First, the subroutine of the FDC processing during the high speed synchronization control will be described with reference to FIG. F in step S615
It is determined whether or not the DC flag is set. In this step, it is judged whether or not the photometric value by the test light emission is incorrect. The case where the photometric value by the test light emission is incorrect is, for example, the case where the photometric value is out of interlock. Succeedingly, in a step S620, LVC ≦
It is determined whether it is LVC _MAX . In this step, L
Since VC _MAX changes depending on the battery voltage, FLATTIME, etc., the determination in step S620 is made. If YES, the flow advances to step S625 to set the FDC flag. The above is the subroutine of the FDC processing at the time of high-speed synchronization control.

Next, FIG. 21 of the subroutine of the FDC processing at the time of normal light emission will be described. In step S630, it is determined whether or not the light emission stop signal has been input within a fixed time. If YES, proceed to step S635, where F
The DC flag is set. The above is the FDC for normal light emission
It is a processing subroutine.

Next, the details of the time chart of the high speed synchronization control in the first mode of FIG. 22 will be described. Symbols appearing in FIG. 22 will be briefly described. Metering with AE and AF,
Focus adjustment is performed. In serial communication, data is exchanged from the camera to the flash, or from the flash to the camera. Release is controlled for RMg, and aperture is controlled for FMg. In SS, the first and second shutters start traveling according to the set shutter speed. Shutter 1 when waiting for 2C
The curtain runs, and waits for the shutter 2 curtain to finish running.
In winding, the film is wound. S1 is a photometry start signal, and S2 is a release signal. INR
EL is a signal generated by the CPU in the camera during release. CSFL is the C in the camera when communicating with the flash.
This is a signal generated in PU. 1CMg is shutter 1
The curtain 2CMg is a signal for causing the magnet holding the shutter 2 curtain to generate a magnetic force or to be demagnetized. F1 is a light emission start signal. SSMODE is
This is a signal indicating whether high-speed synchronization control or normal light emission is performed. FL
ST is a light emission start signal generated by the CPU inside the flash. The IGBT is a signal generated by a circuit in the flash, and is a signal for controlling ON / OFF of light emission of the flash by turning the IGBT on and off at a high frequency. F2 is the data (SO) sent from the flash to the camera and the data (S) sent from the camera to the flash.
It is a signal for performing serial communication of I). F3 is
Timing signal (clock) for SO and SI data communication
Is. TRIGON is a signal for turning on the IGBT. TRIGOFF is a signal for turning off the IGBT. FLGATE is a signal for controlling photometry of flash light. FLSTP is a light emission stop signal.

When the photometry start signal S1 is turned on, "L" is output and focus detection (AF) is performed. Focus detection (A
After step F) is performed, data is communicated from the flash to the camera (serial communication), and then photometry is performed. The serial communication is data communication performed in step S15, and data is input / output from F2. F3 is SO,
A timing signal (clock) for SI data communication is output, and "L" is output from CSFL during serial communication. Then, the exposure calculation is performed, and the exposure calculation result is transmitted from the camera to the flash. The above sequence is repeated until the release signal S2 is turned on (“L” output). When the release signal S2 is turned on (“L” is output), “L” is input from F1, test light emission is performed by the signal, the subject distance (DV) is calculated, and the APEX of the light intensity calculation of step S120 is performed. Formula (LV =
The luminous intensity (LVC) at the time of main light emission is calculated from BV _F + DV). After S2 is turned on and the test flash and the exposure calculation are completed, the release flag is sent from the camera to the flash from F3, and the release of INREL starts with shutter 2
"L" is output until the curtain finishes running. INR
When “L” is output from EL, 1CMg outputs “L” until the start of one-curtain running, and 2CMg outputs “L” until the start of two-curtain running. The first and second focal plane shutters are mechanically locked before the release, but are retained magnetically after the release. This is a configuration for performing accurate shutter travel. Next, the data (LVC) obtained by test light emission is RM.
After the control of g and FMg is completed, it is sent from the camera to the flash. FLST is t1 after the shutter starts running.
After that, in synchronization with F1 becoming "L" (T0-t1)
Represents the state of the flag inside the flash that represents the time of. I
The GBT control signal is output during the flash firing (T0-t
1), ON / OFF is repeated at high frequency, and ON / OFF of flash light emission is controlled in response to this signal.
As described above, the light emission is performed during the high-speed sync control in the first mode.

<Second Mode> Also in the second mode, the camera is controlled by the flowchart shown in the sequence of the camera in FIG.

In the table shown in FIG. 4, step S15,
The contents of data communication performed in steps S30 and S55 will be described. In step S15, data is transmitted from the flash to the camera. Specifically, IV
(A signal indicating the flash light amount), SSEN (a signal indicating that the flash device is capable of high-speed synchronization), and IV
_TEST (signal that indicates the amount of flash light during test _firing ) and I
V _MAX (a signal indicating the maximum amount of light that can be emitted), IV _MIN (a signal indicating the minimum amount of light that can be emitted), and LV _t (t during test emission)
A signal indicating the flash intensity in seconds) is transmitted from the flash to the camera. In step S30, DV (a signal indicating the subject distance) and TV (a signal indicating the shutter speed)
, FV (signal indicating focal length), SV (signal indicating film sensitivity), AV (signal indicating aperture value), and NOTFIR
E (signal indicating whether or not the flash fires) and FL
ATREQ (high-speed sync controllable signal) and FLAT
TIME (a signal indicating the time for which light is emitted in high-speed synchronization control) is transmitted from the camera to the flash. Step S
At 55, IVC (a signal indicating the amount of emitted light per pulse) is transmitted. For the same reason as in the first mode, the IVC stops the test light emission by calculating the subject distance (DV).

FIG. 23 showing the flowchart of the exposure calculation subroutine in the second mode of step S25 will be described. Note that the shutter speed TV _C and the aperture value AV _C are calculated based on the main subject brightness, but the routine relating thereto is omitted.

The routine for proceeding from step S700 to step S720 is the same as step S200 described above, based on the total flash emission amount IV, the shutter speed, and the emission frequency f during the exposure time, the emission light amount IV per pulse.
This is a routine to proceed when the C is calculated and the IVC is within the maximum and minimum amount of light that can be emitted. Specifically, in step S700, it is determined whether or not the shutter speed TV _C is higher than the flash synchronized shutter speed TV _X.
In this step, it is judged whether or not the high speed sync control is necessary. If YES, the process proceeds to step S705, and the total light emission amount IV of the flash performed during the exposure time is calculated as in step S200 of the above-described normal light emission flowchart (FIG. 7). Next, in step S710, the above IV, shutter speed TV _C, and emission frequency f
And from the amount of light emission IVC per pulse (IVC = IV +
TV _C -Log ₂ f) is calculated. The light emission frequency may be a predetermined frequency preset in the camera, or the light emission frequency may be changeable according to the shutter speed. If NO in step S700, the process proceeds to step S702, and the steps shown in FIG.
The process proceeds to the normal light emission flowchart shown in FIG. In addition,
The subject distance (DV) in step S705 is the subject distance calculated from the defocus amount as in the first mode. In step S715, IV _{MIN *} ≤ IVC ≤ IV
_It is judged whether it is _{MAX *} or not. Here, IV _{MIN *} is the minimum amount of light emission per pulse during light emission, and IV _{MAX *} is 1 during light emission.
It is the maximum amount of light emission per pulse. In this step, it is determined whether or not control is possible with the emitted light amount IV _{C *} per pulse. If YES in step S715, the flow proceeds to step S720, and the high speed sync flag is set. If NO in step S715, the process proceeds to step S730.

The routine which proceeds from step S730 to step S720 is 1 calculated in step S710.
This is a routine to proceed when the amount of emitted light per pulse IV _{C *} cannot be controlled. Specifically, in step S730, the aperture value AV _C is recalculated by shifting the shutter speed TV _C and the flash synchronized shutter speed TV _X by the number of steps difference, and in step S735, the shutter speed T _C is calculated.
The flow chart (FIGS. 7 and 8) of the normal light emission is performed by setting V _C to the flash synchronized shutter speed TV _X. The above is the description of the flowchart of the exposure calculation subroutine in the second mode.

Next, the subroutine of the high-speed sync control in the second mode, which is performed in step S55, will be described with reference to FIG.
It will be described based on. In the second mode, the test light emission is performed as in the first mode, the subject distance (DV) is calculated from the main subject brightness during the test light emission and the main subject brightness due to the constant light, and the main light emission is performed based on the subject distance (DV). The amount of light per pulse is calculated. Test light emission is performed in step S840, and then the process proceeds to step S845 to calculate the main subject brightness during test light emission. Then step S8
In step 50, the subject distance is calculated. Here, the calculation of the subject distance by the test light emission in the second mode will be described. BV1 is the brightness of the main subject by constant light, BV4 is the brightness of the main subject t seconds after the start of light emission, and LV _T is the luminous intensity t seconds after the start of test light emission. The luminance change of the main subject luminance due to the test light emission is changed to BV5 (BV5 = BV4−BV
1), the subject distance (D
V) is calculated.

DV = LV _T -BV1-log ₂ (2 ^BV5-1 ) If the amount of light emitted during test light emission is fixed, LV _T
Is known data, and the light intensity after t seconds from the start of the test light emission may be detected by a light receiving element arranged under the flash panel to obtain the value. As another method of calculating the subject distance, the subject distance is calculated from the difference between the predetermined light amount by the test light emission (light receiving amount of the light receiving element at the predetermined distance) and the light receiving amount of the light receiving element at the time of shooting (light receiving amount at the shooting distance). You may use the method of calculating | requiring.

Subsequently, the flow proceeds to step S855, and the light amount at the time of main light emission is calculated based on the calculated subject distance (DV). Amount IVC of emitted light during main emission per pulse
Is the APEX expression (IV = AV shown in step S705).
IV obtained by _C + ΔEV _N + DV-SV),
From the control shutter speed TV _C and the emission frequency f (IV
C = IV + TV _C -log ₂ f) Calculated. Succeedingly, in the step S860, the mirror raising and the narrowing down are started, and then the process proceeds to the step S865 and the above step S855.
The amount of light emission (IVC) per pulse made in step 1 is transmitted from the camera to the flash. Then, step S870.
Then, the shutter travels and the main flash is made. The above is the second mode high-speed sync control subroutine.

The operation of the flash control circuit (FIG. 16) during the high speed sync control in the second mode will be described. At the start of flash light emission, "L" is input from TRIGON to the set terminal of the flip-flop, and the flip-flop operates to output "H". Moreover, since "H" is always input to the OR4 from the F / PMODE terminal, the "H" is always input to the AND2.
Is entered. Therefore, the IGBT control signal at the time of flash emission becomes "H". It should be noted that, with the above configuration, the IG
The BT control signal corresponds to the output from the flip-flop regardless of the output from COMP. N
Since "H" is input to the AND2 from the F / PMODE terminal, the output of the NAND2 is determined by the input from the OR3. One input to OR3 is output from NAND1. One input of NAND1 is output from OR1 to which the outputs of F2 and F3 are input. F2 always outputs "H" during flash emission, and F3 always outputs "L" during flash emission. Therefore, the output "H" from OR1 is input to one of the NAND1s. This configuration is a configuration for switching between control by the camera and control by the flash. The other input of NAND1 is output from OR2 to which the outputs of FLSTP and FLGATE are input. Therefore, the signal from the flash control circuit (FLSTP, FLGATE) causes the NAN
The output from D1 is controlled. Also, during the flash emission, "L" is output from TRIGON, while the IGBT control signal is "H" while "H" is output from FLSTP, and until "L" is output from TRIGON again. The IGBT control signal becomes "L". In this way, by repeating the output of the IGBT control signals "H" and "L" at a high frequency, it is possible to control to continuously perform high frequency pulse light emission.

A time chart of the high speed synchronization control in the second mode in FIG. 24 will be described. When the photometry start signal S1 is turned on, "L" is output and focus detection (AF) is performed.
After focus detection (AF) is performed, data is communicated from the flash to the camera (serial communication), and then photometry is performed. The serial communication is data communication performed in step S15, and data is input / output from F2. F
3 outputs a timing signal (clock) for communication of SO and SI data, and outputs from CSFL during serial communication.
Then, the exposure calculation is performed, and the exposure calculation result is transmitted from the camera to the flash. The above sequence is repeated until the release signal S2 is turned on (“L” output). When the release signal S2 is turned on (“L” is output), “L” is input from F1, and test light emission is performed by the signal to calculate the subject distance (DV), and then step S705 and step S7.
The APEX formula (IV = AV _C + D) for calculating the light amount shown in FIG.
V + △ EV _N -SV and IVC = IV + TV _C -Log
₂ f) to the amount of light emitted per pulse (IV
Calculate C). After S2 is turned on and the test emission and the exposure calculation are completed, the release flag is transmitted from the camera to the flash from F3, and "L" is output to INREL from the start of the release to the end of the movement of the second shutter. When INREL outputs “L”, 1CMg outputs “L” until 1 curtain running, and 2CMg outputs 2
"L" is output until the curtain starts running. Next, the data (IVC) obtained by the test light emission is sent from the camera to the flash after the control of RMg and FMg is completed. FLS
T is F1 after t1 from the start of shutter operation
Represents the state of the flag inside the flash which represents the time (T0-t1) in synchronization with the change to "L". Shutter 1
After the curtain run, TRIGO is set on the flip-flop.
"L" is input from N, the flip-flop operates, and "H" is output. In addition, the OR4 has a F / PMO
Since "H" is always input from the DE terminal, "H" is always input to AND2. Therefore, the IGBT control signal at the time of flash emission becomes "H". With the above-described configuration, the IGBT control signal corresponds to the output from the flip-flop regardless of the output from COMP. From the F / PMODE terminal to NAND2 ”
Since H ″ is input, the output of NAND2 is determined by the input from OR3. One input to OR3 is NAN
It is output from D1. One input of NAND1 is F
The outputs of 2 and F3 are output from the input OR1. F2
"H" is always output when the flash is emitted, and "L" is always output when F3 is emitted by the flash. Therefore, the output "H" from OR1 is input to one of the NAND1s. This configuration is a configuration for switching between control by the camera and control by the flash. Also, N
The other input of AND1 is FLSTP, FLGAT
The output of E is output from the input OR2. Therefore, the signals (FLSTP, FLGAT) from the flash control circuit
The output from NAND1 is controlled by E). TRI
When "L" is input to GON, the IGBT control signal is "
It becomes H ”and the light emission starts.“ L ”on FLSTP
When is input, the IGBT control signal becomes "L" and the light emission stops. In this way, the IGBT control signals "H", "
By repeating the output of L ″ at a high frequency (between T0 and t1), it is possible to control the continuous high frequency pulse light emission.

<Third Mode> Even in the third mode, the camera is controlled by the same flow as the flowchart shown in the sequence of the camera described above with reference to FIG.

In the table shown in FIG. 4, step S15,
Only the contents of data communication performed in steps S30 and S55 will be described. In step S15, data is transmitted from the flash to the camera. In particular,
IV (a signal indicating the amount of flash light), SSEN (a signal indicating that the flash device is capable of high-speed synchronization), IV _MAX (a signal indicating the maximum amount of light that can be emitted) and IV _MIN (a signal indicating the minimum amount of light that can be emitted) are flashed. Sent to the camera from. In step S30, DV (signal indicating subject distance), TV (signal indicating shutter speed), and FV
(A signal indicating the focal length), SV (a signal indicating the film sensitivity), AV (a signal indicating the aperture value), NOTFIRE (a signal indicating whether or not the flash fires), and FLATR
EQ (high-speed sync controllable signal) and FLATTIM
E (a signal indicating the time for which light is emitted in high-speed synchronization control) and IVC (a signal indicating the amount of light emitted per pulse) are transmitted from the camera to the flash. In step S55, data communication from the camera to the flash is not performed.

The dimming circuit of FIG. 25 including the light receiving element arranged at the bottom of the above-mentioned camera will be described. Reference numeral 20 denotes a light receiving element, which is arranged at the bottom of the camera and receives the reflected light from the film. The current output from the light receiving element is input to OP2. OP2 is an operational amplifier, and the output current from OP2 is converted into a voltage logarithmically compressed by the diodes D4 and D5 and output.
The D / A addition circuit is a circuit provided for the purpose of adjusting the film sensitivity according to the set film sensitivity. TR5
Is a transistor provided to convert the logarithmically compressed output voltage output from the operational amplifier (OP2) into a logarithmically expanded current. D6 is the same as the transistor,
It is provided to convert the logarithmically compressed output voltage output from the operational amplifier into a logarithmically expanded current. The electric charge accumulated in the capacitor (C5) corresponds to the output from the light receiving element, and the electric potential accumulated in the capacitor (C5) and the variable power source are compared by the comparator (COMP) to output the light emission start and stop signals. Output. The light emission start and stop signals output from the comparator (COMP) are sent to the I / O circuit (input / output interface),
The signal is transmitted to the CPU and flash circuit. The dimming circuit is also capable of monitoring the luminous intensity.
When monitoring the luminous intensity, a current may flow through the transistor (TR6). The current flowing through TR6 corresponds to the output from the light receiving element 20, and this current and the current output from the variable power source are compared (COM).
Light emission control is performed in comparison with P). With this configuration, the light intensity control in the first mode can be controlled by the light emission control signal from the light control circuit in the camera. The above is the description of the light control circuit.

FIG. 26 showing the flowchart of the exposure calculation subroutine in the third mode of step S25 will be described. The shutter speed T
V _C and the aperture value AV _C are calculated from the brightness of the main subject output from the photometric circuit. Step S750
~ Step S765 is the above step S700 of FIG.
The description is omitted because the same control is performed as in step S715. If YES in step S765, the flow advances to step S770 to determine the film sensitivity SV, the exposure correction amount ΔEV _N (constant) that contributes to the exposure of the main subject during flash emission, the control shutter speed TV _C, and the emission frequency f. The calculated dimming level SV-DA (S
The calculation of V-DA = SV-ΔEV _N -TV _C + Log ₂ f) is performed. Next, proceeding to step S775, the high speed sync flag is set. If NO in step S765, the process proceeds to step S785. Step S7
85 to step S790 corresponds to step S73 of FIG.
Since the same control as 0 to step S735 is performed, the description thereof will be omitted.

FIG. 31 shows the subroutine of the high-speed sync control in the third mode, which is performed in step S55.
It will be described based on. In step S880, mirror up and focusing are started. Then, step S88.
Proceeding to step 5, the shutter travel and the main flash are performed. At the time of main light emission, as described above, the light control circuit arranged in the camera monitors the reflected light from the subject, and the light emission is started and stopped a predetermined number of times based on the light emission frequency.
The above is the description of the subroutine of the high-speed sync control in the third mode.

A time chart of the high speed synchronization control in the third mode in FIG. 27 will be described. When the photometry start signal S1 is turned on, "L" is output and focus detection (AF) is performed.
After focus detection (AF) is performed, data is communicated from the flash to the camera (serial communication), and then photometry is performed. The serial communication is data communication performed in step S15, and data is input / output from F2. F
3 outputs a timing signal (clock) for communication of SO and SI data, and outputs from CSFL during serial communication.
Then, the exposure calculation is performed, and the exposure calculation result is transmitted from the camera to the flash. The above sequence is repeated until the release signal S2 is turned on (“L” output). When the release signal S2 is turned on (“L” is output), the release flag is sent from the camera to the flash from F3, and the INREL is “L” from the time when the release starts until the second shutter curtain finishes running. When INREL outputs "L", 1CMg outputs "L" until the start of one-curtain running, and 2CMg outputs "L" until the start of two-curtain running FLST. Is t1 after the shutter starts running
After that, in synchronization with F1 becoming "L" (T0-t1)
Represents the state of the flag inside the flash that represents the time of. After running one shutter, "L" is input from TRIGON to the set terminal of the flip-flop, and "H" is output from the flip-flop in response to the input. F / PMO
Since "H" is output from DE, OR4 to AN
Since "H" is output to D2, the IGBT control signal becomes "H", and the flash emission starts. In addition,
Since FLGATE continues to output "H" during flash emission, the transistor (TR4) is turned on and the comparator (COMP) stops operating. Since the flash starts emitting light, the output from F3 is switched from "L" to "H" from the light receiving element arranged at the bottom of the camera, and "L" is output from NAND2 to AND1, so the flip-flop is reset and AND2 The IGBT control signal output from is switched to "L". Then again TRIGO
The IGBT control signal outputs "L" until "L" is output from N and the flip-flop is set. As described above, by repeating the output of the IGBT control signals “H” and “L” at a high frequency, it is possible to control the continuous high frequency pulse light emission.

<Fourth Mode> In the fourth mode, the camera is controlled by the same flow as the flow chart shown for the sequence of the camera described above with reference to FIG.

In the table shown in FIG. 4, step S15,
Only the contents of data communication performed in steps S30 and S55 will be described. In step S15, data is transmitted from the flash to the camera. In particular,
IV (a signal indicating the amount of flash light), SSEN (a signal indicating that the flash device is capable of high-speed synchronization), IV _MAX (a signal indicating the maximum amount of light that can be emitted) and IV _MIN (a signal indicating the minimum amount of light that can be emitted) are flashed. Sent to the camera from. In step S30, DV (signal indicating subject distance), TV (signal indicating shutter speed), and FV
(A signal indicating the focal length), SV (a signal indicating the film sensitivity), AV (a signal indicating the aperture value), NOTFIRE (a signal indicating whether or not the flash fires), and FLATR
EQ (high-speed sync controllable signal) and FLATTIM
E (a signal indicating the time for which light is emitted in high-speed synchronization control) and IVC (a signal indicating the amount of emitted light per pulse) are transmitted from the camera to the flash. In addition, step S55
Then, there is no data communication from the camera to the flash.

Since the flow chart of the exposure calculation subroutine in the fourth mode in step S25 is the same as the flow chart of the exposure calculation subroutine in the second mode, description thereof will be omitted.

Next, the subroutine of the high-speed sync control in the fourth mode performed in step S55 will be described with reference to FIG.
It will be described based on. In step S890, mirror up and focusing are started. Then, step S89.
Proceeding to step 5, the shutter travel and the main flash are performed. During the main light emission, as described above, the light emission amount is monitored by the flash, the light emission is stopped when the appropriate light amount calculated in step S710 is reached, and the light emission is started and stopped a predetermined number of times based on the light emission frequency. The above is the description of the subroutine of the high-speed synchronization control in the fourth mode.

A time chart of the high speed synchronization control in the fourth mode of FIG. 28 will be described. When the photometry start signal S1 is turned on, "L" is output and focus detection (AF) is performed.
After focus detection (AF) is performed, data is communicated from the flash to the camera (serial communication), and then photometry is performed. The serial communication is data communication performed in step S15, and data is input / output from F2. F
3 outputs a timing signal (clock) for communication of SO and SI data, and outputs from CSFL during serial communication.
Then, the exposure calculation is performed, and the exposure calculation result is transmitted from the camera to the flash. The above sequence is repeated until the release signal S2 is turned on (“L” output). When the release signal S2 is turned on (“L” is output), the release flag is sent from the camera to the flash from F3, and the INREL is “L” from the time when the release starts until the second shutter curtain finishes running. When INREL outputs "L", 1CMg outputs "L" until the start of one-curtain running, and 2CMg outputs "L" until the start of two-curtain running FLST. Is t1 after the shutter starts running
After that, in synchronization with F1 becoming "L" (T0-t1)
Represents the state of the flag inside the flash that represents the time of. After running one shutter, "L" is input from TRIGON to the set terminal of the flip-flop, and "H" is output from the flip-flop in response to the input. F / PMO
Since "H" is output from DE, OR4 to AN
Since "H" is output to D2, the IGBT control signal becomes "H", and the flash emission starts. In synchronization with this, "L" is output from FLGATE, the transistor (TR4) is turned off, and the comparator (C
OMP) is activated. When the flash starts emitting light, FLSTP output from the comparator (COMP) becomes "
When H ”is changed to“ L ”(the charge accumulated in C4 becomes a certain amount or more), NAND2 is changed to AND1
Since L "is output, the flip-flop is reset and the IGBT control signal output from AND2 is" L ".
Switch to. Then, "L" is output from TRIGON again, and the IGBT control signal outputs "L" until the flip-flop is set. As described above, by repeating the output of the IGBT control signals “H” and “L” at a high frequency, it is possible to control the continuous high frequency pulse light emission.

Further, in the fourth mode, the details of the high-speed synchronization control by the pulsed light emission have been described, but the high-speed synchronization control by the light emission mode of the first mode, that is, the flat light emission may be performed.

[0106]

According to the first aspect of the present invention, when the flash is emitted in the case of slit exposure, the main subject is illuminated by the flash based on the output from the subject distance calculating means and the brightness to be the reference for the exposure control of the camera. Since the luminous intensity is calculated from the brightness and the constant luminous intensity (flat emission) is controlled by the calculated luminous intensity, even if you leave it to the camera, you can get an exposure that suits the shooting scene ( You can shoot with a proper exposure. Furthermore, the photographer can concentrate on shooting, and even a beginner can easily handle the flash.

According to a second aspect of the present invention, when the flash light is emitted when the slit exposure is performed, the total amount of flash light emitted during the exposure time and the output from the photometric means capable of detecting the brightness due to the stationary light are output. The amount of light emitted per pulse is calculated from the control shutter speed and the flash emission frequency during main flashing, which is calculated based on the calculated amount of light, and high-frequency pulses are continuously emitted with the calculated amount of light (pulse emission). Since the camera is controlled, it is possible to shoot with an exposure that matches the shooting scene (appropriate exposure that takes into account the shooting effects unique to the shooting scene), even if shooting is left to the camera. Furthermore, the photographer can concentrate on shooting, and even a beginner can easily handle the flash.

According to a fourth aspect of the present invention, the standard for controlling the start and stop of light emission for each pulse of pulsed light emission in which a high-frequency pulse is continuously emitted at a constant light amount during flash light emission performed in the case of slit exposure. Controlled by light emission with a constant light amount (pulse light emission) that continuously emits a high-frequency pulse in accordance with the output from the light adjustment means for monitoring whether or not the film exposure has been performed during the main light emission up to the light control level As a result, even if the camera is left alone, it is possible to shoot with an exposure that matches the shooting scene (appropriate exposure that takes into account the shooting effects unique to the shooting scene). Furthermore, the photographer can concentrate on shooting, and even a beginner can easily handle the flash.

[Brief description of drawings]

FIG. 1 is a block diagram of an entire camera system.

FIG. 2 is a table showing an outline of control in each mode.

FIG. 3 is a flowchart showing a sequence of a camera.

FIG. 4 is a table showing communication data for each mode.

FIG. 5 is a flowchart showing a subroutine of exposure calculation in backlight, normal light, and forced light emission in the first mode.

FIG. 6 is a flowchart showing a subroutine of exposure calculation in backlight, normal light, and forced light emission in the first mode.

FIG. 7 is a flowchart showing a subroutine of exposure calculation at the time of backlight, normal light, and forced light emission in the first mode.

FIG. 8 is a flowchart showing a subroutine of exposure calculation in backlight, normal light, and forced light emission in the first mode.

FIG. 9 is a flowchart showing a subroutine of exposure calculation in darkness in the first mode.

FIG. 10 is a flowchart showing a subroutine of exposure calculation in darkness in the first mode.

FIG. 11 is a flowchart showing a subroutine of exposure calculation in A, S, and M modes of the first mode.

FIG. 12 is an external view of a flash device.

FIG. 13 is a connection diagram between a camera and a flash.

FIG. 14 is a diagram showing the contents of serial communication.

FIG. 15 is a diagram showing a flash light emitting circuit.

FIG. 16 is a diagram showing a flash control circuit.

FIG. 17 is a flowchart showing a flash sequence.

FIG. 18 is a flowchart showing a flash sequence.

FIG. 19 is a flowchart showing a flash sequence.

FIG. 20 is a flowchart showing a flash sequence.

FIG. 21 is a flowchart showing a flash sequence.

FIG. 22 is a diagram showing a time chart of high-speed sync control in the first mode.

FIG. 23 is a flowchart showing a subroutine of exposure calculation in second mode and fourth mode.

FIG. 24 is a diagram showing a time chart of high-speed synchronization control in the second mode.

FIG. 25 is a diagram showing a dimming circuit.

FIG. 26 is a flowchart showing a subroutine of exposure calculation in a third mode.

FIG. 27 is a view showing a time chart of high-speed sync control in a third mode.

FIG. 28 is a diagram showing a time chart of high-speed synchronization control in a fourth mode.

FIG. 29 is a flowchart showing a subroutine of high-speed sync control in the first mode.

FIG. 30 is a flowchart showing a subroutine of high-speed sync control in the second mode.

FIG. 31 is a flowchart showing a subroutine of high-speed sync control in the third mode.

FIG. 32 is a flowchart showing a subroutine of high-speed sync control in a fourth mode.

[Explanation of symbols]

 1 Focus Detection Circuit 2 Lens Drive Circuit 3 Photometry Circuit 4 Shutter Control Circuit 5 Aperture Control Circuit 6 Charge Circuit 7 Film Winding Circuit 8 Light Control Circuit 9 Flash Device 10 Film Sensitivity Detection Circuit 11 Lens ROM 12 DC-DC Converter 13 Light-Receiving Element

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Otsuka 2-3-13 Azuchi-cho, Chuo-ku, Osaka Inside the Osaka International Building Minolta Camera Co., Ltd. (72) Keizo Kioku, Azuchi-cho, Chuo-ku, Osaka 3-13-3 Osaka International Building Minolta Camera Co., Ltd. (72) Inventor Atsuhisa Ohno 2-33-1 Azuchi-cho, Chuo-ku, Osaka City Osaka International Building Minolta Camera Co., Ltd.

Claims (4)

[Claims] 1. A subject distance calculating means for calculating a subject distance, a photometric means capable of detecting the luminance by ambient light, and a luminance which is obtained from an output of the photometric means and should be a reference for exposure control of a camera. Calculating means, and a luminous intensity calculating means for obtaining the luminance of the main subject irradiation by the flash from the luminance to be the reference of the exposure control of the camera, and for obtaining the luminous intensity from the luminance of the main subject irradiation by the flash and the subject distance, A flash dimming system comprising: a flat light emission control unit that controls light emission at a constant light intensity according to an output from the light emission intensity calculation unit. 2. A photometric means capable of detecting the brightness of constant light, an emission frequency output means for outputting the flash emission frequency, a total flash emission amount during the exposure time, and the above-mentioned photometric means. Calculated from the control shutter speed for main flash obtained from the output and the flash emission frequency 1
And a pulse light emission control unit for controlling light emission in which a high-frequency pulse is continuously emitted at a constant light amount according to the output from the light emission amount calculation unit per pulse. Flash dimming system featuring. 3. The subject distance calculated by the subject distance calculating means is obtained from the luminous intensity at the time of test light emission performed before the main light emission, the main subject luminance by the stationary light, and the luminance change amount of the main subject luminance by the test light emission. The flash dimming system according to claim 1, wherein: 4. A dimming level calculating means for calculating a dimming level serving as a reference for control of light emission start and light emission stop for each pulse of pulsed light emission in which high frequency pulses are continuously emitted with a constant light amount, Light control means for monitoring whether or not the film exposure amount at the time of light emission reaches the above-mentioned light control level, and light emission for continuously performing high-frequency pulses with a constant light amount according to the output from the light control means And a pulsed light emission control means for controlling the flash light control system.