JPH02108030A - Stroboscope incorporating camera capable of loading external stroboscope - Google Patents

Abstract

PURPOSE:To take a picture as a photographer intends by detecting that a specific mode is selected among stroboscopic photographing modes and inhibiting flashing of a built-in stroboscope. CONSTITUTION:When specific modes such as a manual flash mode, a 2nd blade flash mode, a multiflash mode, a continuous photographing mode, an external dimming mode and an FEL mode are selected out of various stroboscopic photographing modes established in combination with an external stroboscope 204 and the camera 201, with the external stroboscope 204 loaded on the stroboscope incorporating camera 201, the flash of the built-in stroboscope 203 is inhibited. Consequently, a photographer can take a picture in his desirable way under stroboscopic photographing by loading the external stroboscope 204 on the stroboscope incorporating camera 201.

Description

Detailed Description of the Invention (Field of Application of the Invention) The present invention provides a method for attaching an external strobe device for multiple flashes to a camera with a built-in strobe device, communicating with the camera, and controlling the light emission according to the strobe photography shooting mode that is set. This invention relates to an improvement of a camera with a built-in strobe that can be attached to an external strobe device.

(Background of the Invention) In recent years, some eye reflex cameras with a built-in strobe device have appeared, and the built-in strobe device and an external strobe device are often used in parallel for the purpose of increasing the number of flashes. In this case, there is no problem when using an automatic mode such as TTL flash control, but if you use a special mode of an external strobe device and fire two flashes, one internal and one external, for strobe photography, the result will be In some cases, the photograph taken was different from what the photographer had intended, or the photograph was defective. An example of a case where a special mode is selected and the problems associated with it will be described below.

1) When the mode of the external strobe device is set to manual flash mode (a mode in which the flash output is manually set) In this case, the guide number is calculated based on the full flash output of the external strobe device, so the built-in strobe device The amount of light emitted increases accordingly, and there is a possibility that the situation will be overexposed compared to what the photographer had in mind. This is almost the same when the external strobe is in FEL mode (the exposure amount from the pre-flash of the main light emitting unit performed prior to photographing is memorized and the exposure is controlled according to the exposure amount at the time of photographing).

2) When the mode of the external strobe device is set to rear curtain light emitting moto For example, if the built-in strobe device fires at the leading curtain run completion signal, and the external strobe device fires at the timing when the trailing curtain starts running, the flash will not fire. The timing is different, and the effect of the rear-curtain flash mode is impaired, resulting in a photograph that differs from the intended one. The same applies if the built-in and external strobes have different light emission timings.

3) When the mode of the external strobe device is set to multi-flash mode The multi-flash mode of the external strobe device means that multiple flashes of a constant amount of light are emitted for each shooting, and the built-in strobe device If you synchronize them, the first shot will be synchronized, but after the second shot, the built-in strobe device will not be recycled in time, and the exposure amount will not be constant.

4) When the mode of the external strobe device is set to snapshot mode (-When taking snapshots while fishing on a boat, use the manual flash Lo mode that allows multiple flashes with a constant light intensity to ensure multiple flashes. In this case, as in 3) above, the built-in strobe device can be synchronized for the first shot, but after the second shot it cannot be recycled in time, and the exposure must always be constant during quick shooting. It's difficult. Furthermore, when multiple flash flashes are used for continuous shooting, this effect becomes more pronounced, resulting in overexposure only when the built-in strobe device is fully charged in time, resulting in a failed photograph.

5) If the external strobe device is an external flash control type or one that can be switched to external flash control - For boat fishing cameras, the external flash device does not send a light emission stop signal to the built-in flash device, so the external flash device When a strobe device is attached, the amount of light emitted by the built-in strobe device cannot be controlled, and there is a possibility that overexposure will occur by the amount of light emitted by the built-in strobe device after the external strobe device stops emitting light.

Furthermore, a proposal for attaching an external strobe device to a camera with a built-in strobe and selectively emitting one of them is disclosed, for example, in Japanese Patent Application Laid-Open No. 59-58425. The built-in strobe device is disabled and only the external strobe device can emit light. However, in such a camera, increasing the number of lights is contrary to the intention.

(Objective of the Invention) The present invention solves the above-mentioned problems and makes it possible to always perform photography in accordance with the photographer's wishes in strobe photography performed with an external strobe device attached to a camera with a built-in strobe. An object of the present invention is to provide a camera with a built-in strobe that can be attached to an external strobe device.

(Features of the Invention) In order to achieve the above object, the present invention provides a detection means for detecting that a particular mode is selected among the strobe photography modes selected when an external strobe device is attached. , and a light emission prohibiting means for prohibiting the built-in strobe device from emitting light based on the detection by the detection means, so that when the external strobe device is attached to the camera with a built-in strobe, it is possible to combine the external strobe device and the camera. When a certain mode is set among the various strobe shooting modes, such as manual flash mode, rear-curtain flash mode, multi-flash mode, continuous shooting mode, external flash mode, or FEL mode, the built-in strobe device fires. The feature is that it is prohibited.

(Embodiments of the Invention) Hereinafter, the present invention will be described in detail based on illustrated embodiments.

FIG. 3 is a side view showing a state in which an external strobe device is attached to a camera with a built-in strobe according to an embodiment of the present invention;
1 is a camera body, 202 is a zoom lens, 203 is a built-in strobe device disposed in the camera body (hereinafter referred to as a built-in strobe in the embodiment), 204 is an external strobe device (hereinafter referred to as an external strobe in the embodiment), 20
5 is a condensing lens, and 206 is a light emitting unit.

FIG. 2 is a circuit block diagram of the external strobe 204 shown in FIG. 2, and FIG. 1 is a circuit block diagram of the camera control circuit in the camera body 201 and the built-in strobe 203.

In this first embodiment, the external strobe has an FEL mode and a trailing curtain light emission mode, and the details of the configuration will be described below.

In Fig. 2, 1 is a battery connected in series to the power switch 2, and 3 is a DC/D device that boosts the voltage of the power supply battery 1.
The C converter 4 is a capacitor that stores the energy of the flash light, and its capacity is the capacitor 56 as described later.
smaller than the capacity of. 5.6 is a resistor that bleeds the voltage of the capacitor 4, 7 is a comparator that detects the completion of charging of the capacitor 4 (hereinafter referred to as "charging complete"), 9 is an LED for indicating charging completion with a resistor 8 connected in series, 11 is Xe a discharge tube, 10 a trigger circuit for starting the discharge tube 11 to emit light;
12 is a control circuit for serial dimming, 13 is an OR gate (hereinafter referred to as OR), and 14 is a NOR gate (hereinafter referred to as NOR).
), 15 and 16 are switches composed of FETs, etc., which are turned off when the control signal is at the L level and turned on when the control signal is at the H level. 19 is a photodiode located near the Xe discharge tube 11 and detects the amount of light emitted from it, 17.1
Reference numerals 8 and 20 denote a capacitor and an operational amplifier, respectively, constituting a known optical integrator circuit a.

21 is an A/D converter with comparators connected in parallel, 22 is a latch circuit, 23 is a D/A converter, 24 is a comparator that compares the output of the optical integration circuit H and the output of the D/A converter 23, and 25 is an AND gate. (hereinafter AND
26 is an inverter, 28 is a capacitor, 29 is a diode, 30 is a resistor, 28.
2930 constitutes a differentiation circuit that detects the falling edge of a pulse. 31 is AND, 32 is monostable multi-by-break (hereinafter referred to as one-shot OS), 3
3 is AND, 34 is Inhata, 35 is AND, 36 is B
RS flip-flop with clear function (hereinafter referred to as R3F/F) that is set when a signal to start flashing is input from the terminal, 37, 38. 40 are inhata,
39.41 is 0R142, 47 is AND, 43.44.
45 are capacitors 28. It is the same as the resistor 30 and diode 29, and constitutes a differential circuit. 46 is a comparator that detects whether a voltage is applied to the E terminal;
48 and 49 are resistors that determine the amount of current drawn from the E terminal to the strobe circuit side, and 5o is a switch that switches the camera between front-curtain sync mode and rear-curtain sync mode depending on whether resistor 48 is connected or not. When it is on, it switches to first-curtain sync mode, and when it's on, it switches to second-curtain sync mode.

51 is a transistor that turns on when the comparator 7 becomes H level (full), 52 and 54 are resistors, 53 is a transistor that turns off the transistor 51, and 55 is F
This is a mode changeover switch that changes between EL mode and TTL dimming mode. As mentioned above, 56 is a capacitor that stores energy for main light emission and has a larger capacity than capacitor 4 that stores energy for pre-light emission, and its capacity is determined in relation to the ratio of pre-light emission and main light emission. In other words, in the case where the flash light emission amount is set to 1/N of the main light emission amount, the capacitance of the capacitor 4 is
1/ of the sum of capacitance of capacitor 4 and capacitance of capacitor 56
It is set to be N. Therefore, for example, when the amount of flash light is 1/10 of the amount of main light, the capacitance of the capacitor 4 is set to be 1/9 of the capacitance of the capacitor 56.

Further, the capacitance of the capacitor 1718 in the optical integration circuit H is set similarly. 57 and 58 are backflow prevention diodes, and 59 is a switching device that is turned on when the output of the inverter 34 is at H level, that is, when the X contact on the camera side is turned on, and is turned off when the output of the inverter 34 is at L level. By means of the switching element 59, the energy stored in the capacitor 4 is used to emit light during flash lighting, and the energy stored in the capacitor 4 and the capacitor 56 is used to emit light during main light emission.

The A-F terminals are terminals connected to the camera, the A terminal is an
When the level is reversed from the L level to the L level, the external strobe 204 starts pre-light emission, and when the level is reversed from the L level to the H level, the light emission ends. The C terminal is a terminal that transmits the signal of the shooting mode set on the external strobe 204 side to the camera side.
FEL mode when level, TTL when L level
It means dimming mode. When a H level signal is input to the D terminal, the signal input from the corresponding terminal changes from H level to L.
Until the level is reversed, this is a terminal that prevents strobe light from being emitted even if the signal at the Strobe light emission is stopped by inverting the signal from L level to H level.

The E terminal is a terminal into which a constant voltage applied from the camera side is input, and the front curtain synchronization mode and rear curtain synchronization mode of the camera are determined by the amount of current flowing through the E terminal. The F terminal is a ground terminal.

FIG. 1 is a circuit block diagram of a camera control circuit and built-in strobe 203 arranged in the camera body 201, and Vcc and Vc in the figure are voltages supplied from a power supply circuit (not shown).

In FIG. 3, numeral 60 is a microcomputer (hereinafter referred to as CPU) that controls various operations of the camera, and is a one-chip type (for example, Motorola 6805) having a built-in ROM for programs and RAM for memory. 61-A
is an 8-bit parallel address bus (hereinafter referred to as AD)
, 61-D is an 8-bit parallel data bus (hereinafter referred to as D
(referred to as B). 62.degree. 71.80 is a three-state pass buffer, and switches 63 to 70 are switches provided on an ISO sensitivity setting dial (not shown), through which a coated ISO sensitivity apex value is input. Switch 72~
Reference numeral 79 denotes a switch provided on a lens mount (not shown), through which an apex value encoded as the open FNO of the lens is input. Switches 81 to 88 are switches arranged corresponding to the aperture and shutter speed setting dials, and are used to input the set aperture value and shutter speed. A decoder 89 decodes the signal sent to the address bus 61- of the CPU 60, selects one of the outputs C80 to C38 and sets it to H level, and sets the remaining outputs to L level. 90
is an A/D converter, 91 is a D/A converter,
For input of digital value N (Vc-18mVXN)
It is configured to output a voltage of .

Numerals 92 to 97 are elements constituting a dimming circuit (2) for performing TTL dimming on the camera side. 92 passes through the sub mirror 409 and the half mirror at the center of the mirror 408 when the quick return mirror 408 is placed in the photographing optical path as shown in FIGS. 5-a and 5-b, which will be described later. A light receiving element 93 is a diode 93, and 94 is an operational amplifier 94, which is configured to measure the light at the center of the subject and measure the light reflected from the film surface when the mirror 408 is raised and the shutter is open. The transistor 95 has a base connected to the output of the operational amplifier 94 and an emitter connected to the D/A.
It is connected to the A converter 91, and the collector is the capacitor 9.
6 and is used for expansion. Reference numeral 97 denotes a switch that is turned on when an H level signal is input manually.

In the dimming circuit (2), the photocurrent flowing through the light receiving element 92 increases the output voltage of the D/A converter 91 by (N x It
8 mV), transistor 95
The current flowing through is multiplied by 2N. Also, after the switch 97 is turned off, the collector current of the transistor 95 is ■.

E is integrated by capacitor 96.

98.99 are a constant voltage source and a comparator, respectively.
When the voltage at the connection point between the collector of the transistor 95 and the capacitor falls below Vcc due to integration and becomes lower than the output voltage E F ref of the constant voltage source 98, the voltage accumulated in the capacitor 96 is reversed from the L level to the H level. This circuit constitutes a circuit that indicates that a certain amount of charge has been reached and stops strobe light emission.

Note that this circuit outputs a light emission stop signal to be transmitted to the external strobe 204 shown in FIG. Further, the output of the D/A converter 91, the capacitance of the transistor 96, and the voltage of the constant voltage source 98 are set so that the strobe light emission stops when the appropriate amount of strobe light is irradiated onto the film surface.

Here, for example, the light intensity of 0.11ux, sec to the light receiving element 92 (corresponding to the appropriate exposure amount of ISOloo film)
Assuming that the capacitance of the capacitor 96 and the voltage of the constant voltage source 98 are set so that a light emission stop signal is output from the comparator 99 when
The current between the collector and emitter of is the D/A converter 91.
Since the output of D/A doubles every 18mV change,
When the output of the converter 91 is (V-18mV), the output is 0.21ux, sec, and when the output is (V+18mV), the output is 0.051ux, sec.
A light emission stop signal is output.

100 to 102 are resistors, and 103 is an operational amplifier, which constitutes a circuit that inverts and amplifies the collector voltage of the transistor 95. 104 is a light receiving element that measures the peripheral area of the screen;
05 is a light-receiving element that measures the center of the screen, 106 is an electric switch, 107 is an operational amplifier, 108 is a diode, and 107 and 108 constitute a known logarithmic compression circuit.

When the switch 106 is open, the output of the operational amplifier 107 is a logarithmically compressed photometric value of the brightness at the center of the field. Also, if the switch 106 is closed,
The output is the sum of the photocurrents output by the light receiving elements 104 and 105, that is, the logarithmically compressed photometric value of the brightness of the entire field. Resistors 109 to 111 and operational amplifier 112 constitute an inverting amplifier circuit. 113, 114 are electrical switches, 11
Reference numeral 5 denotes an inverter, which selects the input power to the A/D converter 90 based on a signal from the port P21 of the CPU 60. 116 a magnet for releasing the first tension of the camera and starting the mechanical sequence for release; 11;
8 is a magnet that activates the automatic aperture when energized and stops the automatic iris when de-energized to control the aperture value; 120 is a magnet that drives the front shutter curtain of the camera; 122 is a magnet that controls the aperture value of the camera; Magnet that drives the shutter rear curtain, 117 119 121.1
23 is a transistor for energizing the magnet. Reference numeral 124 denotes an X-connection switch that changes from off to on when the shutter front curtain finishes running, and from on to off when the shutter rear curtain starts running. 125 and 126 are OR. 127129 is a resistor, 128 is an operational amplifier, 13
0 is a transistor, and when the transistor 130 is on, the voltage at the E terminal is grounded, and when it is off, the voltage of Vc is applied, and at the same time, the voltage from the E terminal to the transistor 51 shown in FIG. A circuit is configured to generate a voltage at the output of the operational amplifier 128 corresponding to the current that is removed. Resistors 131 to 133 are voltage dividing resistors that generate a reference voltage for comparator 134135. When a specified current (for example, 250 μA) or more flows from the E terminal, the output of comparator 135 becomes H level, and the output of comparator 135 becomes H level. The resistor 131 is set so that the output of the comparator 134 also becomes H level due to the flow of a larger current (for example, 800 μA) than the
A resistance value of ~133 is set. 136 outputs an L level for a certain period of time when the power is turned on from a power supply circuit (not shown);
After that, the power-up clear circuit outputs H level (
(hereinafter referred to as PUC circuit).

SWI is a switch that is turned on by the first stroke of the release button, SW2 is a switch that is turned on by the second stroke of the release button, SW3 is a switch for flashing, and SW4 is turned on when winding is completed. SW5 is a switch that is turned off when the mirror 408 shown in FIG. SW8 is a switch that turns on and off in synchronization with an aperture member (not shown) and outputs one pulse each time the aperture is narrowed down by one stage, depending on the amount of aperture reduction. SW9, a switch for resetting information obtained by pre-emission, is a switch for switching between aperture-priority photography and shutter-priority photography, and when it is on, shutter-priority photography is selected, and when it is off, aperture-priority photography is selected.

J surrounded by a broken line is a circuit block diagram of a built-in strobe arranged in the camera, and Vcc is a power supply voltage supplied from a power supply device (not shown), and a power switch 152 is connected in series to this power supply. There is. 153 is a transistor, 154 is a capacitor, 155 is an oscillation transformer, 156
is a resistor, and 153 to 156 constitute an oscillation booster circuit. Between the emitter and the pace of the transistor 153 is E.
It is connected to a switching element 157 composed of an FT or the like, and is turned off when the control signal is at L level and turned on when it is at H level. 158 is a capacitor for storing strobe light energy, 159 is a backflow prevention guide, 16
0, 161 is a resistor that bleeds the voltage of the capacitor 158, 162 is a converter that detects the completion of charging of the capacitor 158, 163 is an LED connected in series with a resistor 164 to indicate the completion of charging, and 166 is a Xe discharge tube. , 165 is a trigger circuit for starting generation of the discharge tube 166, 167 is a control circuit for series dimming, 168 is 0R2169,1
70 is each gate of AND, 171 is a capacitor,
172 is a diode, 173 is a resistor, 171, 17
2.173 constitutes a differential circuit that detects the falling edge of a pulse. 174 and 175 are inverters.

The operations of the external strobe and the camera with built-in strobe configured as described above will be explained using the time chart shown in FIG. 4.

First, the switch 55 in the external strobe 204 causes the FE
A case will be described in which the L mode is selected, the C terminal is at H level, the switch 50 is off, and the front curtain synchronization mode is selected.

Switch 2 turns on and DC/DC converter 3
When the voltage of the main capacitor 4 increases, the output a of the comparator 7 is inverted from L level to H level. As a result, the LED 9 lights up and the transistor 51 is turned on (time 1+ in FIG. 4).

Thereafter, when the first stroke of the release button of the camera is turned on at the timing shown at time t2, the SWI of the camera is turned on, a constant voltage is applied to the E terminal, and a specified current flows through the resistor 49. In this case, since the switch 50 is off, the current flowing through the E terminal is relatively small, for example, 200 μA. After that, when the switch SW3 on the camera side shown in FIG. 1 is turned on, the CPU 60
The L level is output from the port P19, the transistor 130 is turned off, and the operational amplifier 128 changes the voltage of the E terminal to V.
c. At the same time boats P15, P
When I3 becomes H level, the signal at the B terminal shown in Fig. 2 rises to H level, photometry for -1 external light is performed, and then the signal at the B terminal once falls to L level (at time t3). When the signal at the B terminal falls from the H level to the L level, the signal inverted by the inverter 37 is input to the trigger circuit IO as a rising signal via the AND35.0R13, and the energy of the capacitor 4 causes the Xe discharge tube 11 to emit light. will be held. At the same time, the output of the NOR 14 becomes L level, the switch 15 is turned off, and the optical integration circuit H starts operating and begins to integrate a portion of the amount of light emitted from the Xe discharge tube 11.

Further, at this time, since the switch 16 is off, only the small capacitance capacitor 18 of the integrating circuit H is connected to the feedback loop of the operational amplifier 20.

Simultaneously with the start of such integration, R3F/F36 is set similarly to the trigger circuit 10, and its Q output goes to H level (
The output is inverted to L level.

The light reflected by the object due to the light emitted by the Xe discharge tube 11 is integrated as described later by the camera's light control circuit shown in FIG. 1, and when it reaches a predetermined level, the signal at the B terminal changes from the L level to the H level. level (time 14). The rise of this signal causes inverter 27. capacitor 28
．． A rising pulse is created by a differentiating circuit consisting of a diode 29 and a resistor 30 (output b in Figure 4), and 0R2
6 to the control circuit 12 to stop the Xe discharge tube 11 from emitting light, and also to the clock input terminal of the latch circuit 22. A/D converter 21 is Xe discharge tube 1
The integral value of a part of the luminescence amount of 1 is always A/D converted,
The result is latched in the latch circuit 22 when the Xe discharge tube 11 stops emitting light. Therefore, the light reflected from the subject caused by the above pre-flash enters the camera, and the amount of light emitted from the Xe discharge tube 11 during the pre-flash when the level of the incident light reaches a predetermined level is stored in the latch circuit 22. will be done.

Next, a case will be described in which the second stroke of the release button of the camera is pressed and the switch SW2 shown in FIG. 1 is turned on.

First, the signal at the D terminal has already risen before the shutter runs. When the shutter runs, the shutter front curtain completes its travel, the X contact turns on, and terminal A goes to L level (
At time t6), since the output of the inverter 40 is at H level at this point, the output of AND33 becomes H level, and the output of one shot 0332 becomes H level.

If the main capacitor 4 continues to be fully charged, AN
The output of D31 is input to the trigger circuit 10 via 0R13, and the Xe discharge tube 11 emits light.

Further, in this case, the X contact is turned on and the switching element 59 is turned on, so that the Xe discharge tube 11 emits light by the energy of the capacitor 56 and the capacitor 4. At the same time A
The output of the ND 42 also becomes H level, turning on the transistor 53 and turning off the transistor 51, and the amount of current drawn from the camera via the E terminal changes. Therefore, by detecting this change on the camera side, the camera side can accurately detect when the main light emission is performed.

At the same time as the Xe discharge tube 11 emits light, the output of the NOR 14 becomes L level, the switch 15 is turned off, and the switch 1 is turned off.
6 is turned on, the capacitance of the capacitor connected to the feedback loop of the operational amplifier 20 of the optical integrating circuit H is the sum of the capacitances of capacitors 17 and 18. Also, the output of the optical integration circuit H while the Xe discharge tube 11 is emitting light is output to the comparator 24.
It is input to the AND 25 and compared with the output of the D/A converter 23, and when they match, the output of the comparator 24 is inverted from L level to H level and input to AND25. Here, as mentioned above, the Q output of the RS F/F 36 is at H level and the switch 55 is selected to FEL mode, so the AND25
The output of
The e-discharge tube 11 stops emitting light. In this case, since the output of 0R39 is L level (the Q output of RS F/F 36 is L level)
level, since the output of inverter 38 is L level), AND
The output e of 47 is also at L level. Therefore, even if a light emission stop signal is output from the D terminal, the controller answer 43. Resistance 44. Even if the positive pulse d is output from the diode 45, the output of the AND 47 is always at the L level, so it cannot be accepted. In other words, when the external strobe 204 is in the FEL mode, the camera has a function to output a light emission stop signal that stops strobe light emission for TTL flash control, and even if the light emission stop signal is output from the camera during strobe light emission. However, the strobe light emission will not be stopped by this signal.

On the other hand, when the external strobe 204 is in FEL mode, the camera's built-in strobe is turned off because the C terminal is at H level.
Since the output of R168 becomes H level and switch 157 is turned on, the pace emitter of transistor 153 is short-circuited and the oscillation booster circuit becomes inoperable. Also, the output of OR168 is H level and the output level of inverter 175 is L level. Therefore, AND169 remains at the L level, and even if the X signal is input, no trigger signal is output and no strobe light is emitted.

In addition, the external strobe 204 is switched to FEL by the switch 55.
At time t in the time chart shown in Figure 4, when the camera is set to remote mode and the release button is pressed to the second stroke without pressing the flash light switch on the camera side.
This will be explained with reference to ll to t18.

If you press the release button to the second stroke without pressing the flash flash switch on the camera side, the signal will not be input from terminal B to the external strobe 204, so the RS F/F 36 will not be set and its Output Q
remains at L level. Therefore, the signal output from the comparator 24 will not be input to the control circuit 12 in accordance with the information latched in the latch circuit 22. When the light emission stop signal input to the D terminal from the camera side, that is, the signal input to the D terminal rises from the L level to the H level, the capacitor 43. Resistor 44 Diode 45
The pulse e generated is inputted to the control circuit 12 via the AND47.0R26, and the light emission of the Xe discharge tube 11 is stopped. Therefore, the external strobe 204 is connected to the switch 55.
Therefore, even if the camera is set to FEL mode, proper exposure can be obtained since strobe light emission is stopped by a light emission stop signal from the camera side unless the camera side emits flash light.

In addition, the TTL dimming mode is selected by the switch 55.
A case will be described in which the terminal is at L level, the switch 50 is off, and the front curtain synchronization mode is selected.

In such a case, since the C terminal is set to L level by switch 55, the output of AND35 is always at L level, and even if the flash light switch is pressed on the camera side,
Even if a signal that inverts from H level to L level is input to the terminal, such signal is not input to the trigger circuit 10. Therefore, no light is emitted.

Also, when the release button is pressed to the second stroke, it is the same as when the external flash 204 is set to FEL mode by the switch 55 and the release button is pressed to the second stroke without pressing the flash light switch on the camera side. It is.

On the other hand, when the TTL flash control mode is selected and the first curtain synchronization mode is selected, the C terminal of the camera built-in strobe is at the L level, and in the first curtain synchronization mode, the output of the comparator 134 is also at the L level. Therefore, OR1
Since the output of transistor 68 is at L level and switch 157 is off, the pace emitter of transistor 153 is not short-circuited and normal oscillation boosting operation is performed. When the full charge signal and the X contact are turned on, AND169 becomes H level, and light emission starts simultaneously with the light emission of the external strobe. When the film surface is irradiated with the appropriate amount of both strobe lights, a light emission stop signal is output from the comparator 99.
When this signal rises from L level to H level, capacitor 171, diode 172 . The pulse signal generated in the resistor 173 is passed through the AND 170 to the control circuit 1.
67, and the light emission of the Xe discharge tube 166 is stopped at the same time as the external strobe.

Next, a case will be described in which the switch 50 of the external strobe is turned on and the trailing curtain synchronization mode is selected.

When the external strobe switch 50 is turned on, the resistor 49
A resistor 48 is inserted in parallel with the E terminal, and the impedance of the E terminal when viewed from the camera side becomes small. Therefore, if a constant voltage is applied to the E terminal, the current flowing from the camera side increases, and it is detected that the rear curtain synchronization mode has been selected on the camera side. In rear-curtain sync, unlike normal (first-curtain sync mode), the camera
Since the terminal is maintained at H level until just before the shutter rear curtain starts running (in the front curtain synchronization mode, the D terminal is inverted from H level to L level just before the shutter front curtain starts running), even if the shutter front curtain starts running, is completed, the X contact turns on, the signal at the A terminal changes from H level to L level, and even if one of the inputs of AND33 becomes H level via inverter 33, the signal at D terminal is inverted to L level. Until this happens, the output of the AND 33 remains at the L level, and no trigger signal is input to the trigger circuit 1o.

Immediately before the shutter trailing curtain starts running, the signal at the D terminal is inverted from the H level to the L level, so a trigger signal is input to the trigger circuit 10 in synchronization with the inversion of the signal, and strobe light is emitted. The other operations are the same as those of the front curtain synchronized mode, so the explanation will be omitted.

On the other hand, when the TTL flash control mode is selected and the rear curtain synchro mode is selected, the output of the comparator 134 changes from L level to H level in FIG. OR168
The output of becomes H level, the switch 157 is turned on, and the pace emitter of the transistor 153 is short-circuited.
The oscillation booster circuit becomes inactive, and the output of OR168 is at H level and the output of inverter 175 is at L level, so AND169 remains at L level, and no trigger signal is output even if the X signal is input. The built-in flash does not fire.

6 and 7 are circuit diagrams showing other embodiments of the present invention, in which FIG. 6 is a circuit block diagram of an external strobe, and FIG. 7 is a circuit block diagram of a camera control circuit and a built-in strobe.

The configuration according to this embodiment eliminates the FEL mode and rear curtain synchronization mode of the embodiment shown in Figs. 1 to 4, and newly provides a switch for switching between TTL dimming and external dimming. The same numbers are given to the component parts.

As new components, 181 shown in Fig. 6 is a switch for switching between TTL dimming and external dimming, 182 is a photodiode that receives reflected light from the main subject, 183 is a Nant gate, and 184 shown in Fig. 7 is a switch for switching between TTL dimming and external dimming. This is a warning display circuit.

The operation of the circuit with the above configuration will be explained below.

First, a case where the external dimming mode is selected by the switch 181 and the C terminal is at H level will be described.

Switch 2 turns on and DC/DC converter 3
When the voltage of the main capacitor 56 increases, the output of the comparator 7 is inverted from L level to H level. As a result, the LED 9 lights up and the transistor 51
turns on. Then press the first button on the camera's release button.
The stroke turns on the SWI shown in FIG. 7, a constant voltage is applied to the E terminal, and a specified current flows through the resistor 49.

Further, the second stroke of the release button of the camera is pressed, and the switch SW2 shown in FIG. 7 is turned on. At this time, first, the signal at the D terminal has fallen before the shutter runs. When the shutter runs, the front shutter curtain completes its advance, the X contact turns on, and the A terminal goes to L level.
Since the output of the inverter 40 is at H level at this point, the output of AND33 is at H level, and the output of one shot 0832 is at H level. If the main capacitor 56 is fully charged, the output of the AND 31 is input to the trigger circuit 10, and the Xe discharge tube 11 emits light. At the same time, the output of AND42 also becomes H level, and transistor 5
3 turns on and transistor 51 turns off,
The amount of current drawn from the camera via the E terminal changes.

Further, the output of the Nant gate 183 becomes L level, the switch 15 is turned off, and the optical integration circuit H composed of 18' and 20182 starts integrating the reflected light from the subject. The output of this optical integration circuit H is input to the comparator 24 and compared with a predetermined value V ref2 corresponding to the appropriate amount of irradiation on the film surface. If they match, the output of the comparator 24 is inverted from L level to H level. , AND2
Enter 5. Since the switch 181 is set to the external dimming mode, the output of the AND 25 becomes H level along with the inversion of the output of the comparator 24, and is input to the control circuit 12 via the 0R 26, so that the Xe discharge tube 11 stops emitting light. At this time, the output of the inverter 38 is at L level, so the AN
The output of D47 is also at L level. Therefore, even if D
A light emission stop signal is output from the terminal, and the capacitor 43. Even if a positive pulse is output from the resistor 44 diode 45, A
Since the output of ND47 is always at L level, it cannot be accepted. In other words, when the external strobe is in external flash control mode, the camera has a function to output a flash stop signal to stop strobe light emission for TTL flash control, and even if the flash stop signal is output from the camera while the strobe is firing. Even if the signal is sent, strobe light emission will not be stopped.

On the other hand, when the external strobe is in the external light control mode, the C terminal of the built-in strobe in the camera is at the H level, so the switch 157 is turned on. For this reason, the base and emitter of the transistor 153 are short-circuited, and the oscillation booster circuit becomes inoperable. Also, the output of the inverter 175 becomes L level, so AND169 remains at L level, and even if the X signal is input manually, No trigger signal is issued and the built-in strobe does not fire. At this time, the warning display circuit 184 lights up to warn that the built-in strobe will not emit light.

Next, a case where the TTL dimming mode is selected by the switch 181 and the C terminal is at L level will be described.

In this case, since the C terminal is set to the L level by the switch 181, the output of the Nant gate 183 is always at the H level, the switch 15 is always on, and the external dimming circuit is not activated. Furthermore, when the release button is pressed to the second stroke, light emission starts due to the generation of the X signal at the A terminal, but as mentioned above, the comparator 2
The signal from the output of the capacitor 43, the resistor 44. A pulse signal generated in the diode 45 is input to the control circuit 12 via the AND47 and 0R26, and the light emission of the Xe discharge tube 11 is stopped.

On the other hand, in the built-in strobe when the TTL dimming mode is selected, the C terminal is at L level, the switch 157 is off, and the pace and emitter of the transistor 153 are not short-circuited and normal oscillation boost operation is performed. conduct. Then, when a fullness signal is received and the X contact is turned on, AND 169 goes to H level, and light emission starts simultaneously with the external strobe.

When both strobes have irradiated the film surface with an appropriate amount, a light emission stop signal is output from the comparator 99, and as this signal rises from the L level to the H level, the capacitor 171. Diode 172. The pulse signal generated in the resistor 173 is passed through the AND 170 to the control circuit 16.
7, the light emission of the Xe discharge tube 166 is stopped simultaneously with the external strobe.

In this second embodiment, the external strobe is equipped with a switch for switching between TTL flash control and external flash control, but it is not necessary to adopt such a configuration, and it is possible to simply use the external strobe with the external flash control attached. , the built-in strobe function may be prohibited. In addition to the above embodiment, even in the case of manual flash mode, which is enabled when an external strobe is attached to the camera, the built-in strobe will be prohibited from operating by detecting that this mode has been entered. It may be configured. Furthermore, it may be configured to detect that the external strobe enters the multi-flash mode, continuous shooting mode, or multi-flash mode and prohibit the operation of the built-in strobe.

According to this embodiment, when an external strobe is attached to a camera with a built-in strobe, manual flash mode, trailing curtain flash mode, and multi flash mode are available.

When set to various modes such as continuous shooting mode, external light control mode, FEL mode, etc., the built-in strobe is prohibited from firing, so it is possible to take photos according to the shooting intention. Become.

(Correspondence between the invention and the embodiment) In this embodiment, the C terminal and OR168 are used as the detection means,
The switch 157 corresponds to a light emission inhibiting means.

(Effects of the Invention) As explained above, according to the present invention, a detection means for detecting that a particular mode has been selected from among strobe photography modes selected with an external strobe device attached; , and a light emission prohibiting means for prohibiting the built-in strobe device from emitting light based on the detection by the detection means, so that when the external strobe device is attached to the camera with a built-in strobe, it is possible to combine the external strobe device and the camera. If a certain mode is set among the various strobe shooting modes, such as manual flash mode, rear curtain flash mode, multi flash mode, continuous shooting mode, external flash mode, or FEL mode, the built-in strobe device Since the flash is now prohibited, when taking flash photography with an external strobe device attached to a camera with a built-in strobe,
It becomes possible to always take pictures according to the photographer's wishes.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the main parts of a camera with a built-in strobe according to an embodiment of the present invention, FIG. 2 is a block diagram of an external strobe, and FIG. 3 is a side view of the camera with a built-in strobe when an external strobe is attached. Figure 4 is a timing chart to help explain the operation of the embodiments in Figures 1 and 2;
Fig. 5A is a diagram showing the optical path during photometry, Fig. 5-B is a diagram showing the optical path during photographing, and Fig. 6 is a block diagram of the main parts of a camera with built-in strobe 0 according to another embodiment of the present invention. FIG. 2 is also a block diagram of the external strobe. 157...Switch, 201...Camera body, 203...Built-in strobe device, 204
・Old...external strobe device, A~F...terminals.

Claims (1)

[Claims] (1) In a camera with a built-in strobe that can be attached to an external strobe device for multiple flashes, a detection means that detects that a particular mode is selected among the strobe shooting modes that are selected with the external strobe device attached. A camera with a built-in strobe to which an external strobe device can be attached, characterized in that it is provided with: and a light emission inhibiting means for prohibiting light emission of the built-in strobe device upon detection by the detection means.