JPS61156238A - Display device of flash-photographing device - Google Patents

Abstract

PURPOSE:To change an aperture value or shutter speed and to pertinently photograph both background and main object, by displaying the difference between an automatically changed controlled exposure value and an appropriate exposure value obtained by photometrically measuring an image plane to be photographed at the time of flash-photographing. CONSTITUTION:Photoreceptor elements 104 and 105 take photometrical values of an image plane to be photographed and output an appropriate exposure value necessary for pertinently photographing the image plane. Moreover, an LCD display section 200 displays the difference between the appropriate exposure value of the elements 104 and 105 and a controlled exposure value calculated from the shutter speed and aperture value at the time of flash-photographing which is changed for flash photographing. Therefore, even when the controlled exposure value is smaller as compared with the appropriate exposure value and a possibility of taking a background under an over-exposure condition exists in the case of day-time synchro-flash photographing desiring to appropriately photograph both the background and object standing under a rear light condition under blue sky, as an example, both the background and object can be photographed pertinently by changing the aperture value or shutter speed.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a flash photography device, and particularly to a display device that displays photography information when performing flash photography.

(Prior art) Conventionally, when a flash device (hereinafter referred to as a strobe device) is attached to a camera and a photograph is taken, the shutter time of the camera is automatically set according to the completion of charging of the main capacitor of the flash device. A camera system that can be stored away was known.

There is also known a camera system in which not only the shutter speed but also the aperture value is automatically set to an appropriate value depending on the completion of charging. According to such a camera system, even if the shutter time is set to a time inappropriate for flash photography, the shutter time is automatically changed and set to the flash synchronization time. , prevents erroneous operations such as slit exposure caused by forgetting to change the shutter speed! It was very convenient because it allowed users to use the

However, in such camera systems, the shutter speed and even aperture value are automatically set when the strobe device is fully charged, so the strobe is not used when shooting a subject that is backlit against a bright background. The exposure value is determined by the shutter speed and aperture value that are automatically set when performing so-called daytime synchro photography, which ensures that both the background and the main subject are properly exposed.The exposure value measures the outside light. The appropriate exposure value obtained in this manner does not necessarily match, and in such a case, it is not possible to perform daytime synchronized photography in which both the background and the main subject are appropriate. Further, in such a case, a display device that displays the deviation between the control exposure value and the appropriate exposure value and prompts the photographer to change the aperture value has not been known.

<Invention 11 The present invention solves such conventional drawbacks, and uses a strobe device that performs so-called pre-flash to determine the light emission amount of the main flash, so that both the main subject and the background can be properly photographed even in dark synchronized photography. It is an object of the present invention to provide a display device that displays whether or not the flash photography is possible, and based on this purpose, the present invention provides a control exposure value based on a combination of an aperture value and a shutter speed that are automatically determined to be suitable for flash photography. The present invention is characterized by providing a display device that displays the deviation between the exposure value and the appropriate exposure value obtained by photometering external light.

<Embodiment> FIG. 1 is a circuit block diagram of a strobe device according to an embodiment of the present invention.

In Figure 1, 1 is a battery connected in series to the power switch 2, 3 is a DC/DC converter that boosts the voltage of the power battery 1, and 4 is a capacitor that stores the energy of pre-emission, the capacity of which will be described later. smaller than the capacitance of capacitor 56).

5.6 is a resistor that reads the voltage of the capacitor 4, 7 is a comparator that detects the completion of charging of the capacitor 4 (hereinafter referred to as "completion"), 9 is an LED connected in series with a resistor 8 for indicating the completion of charging, and 11 is an Xe a discharge tube; 10 is the discharge tube 11;
13 is a trigger circuit that starts the light emission, a control circuit that performs 12 series dimming, and 13 is an OR gate (hereinafter referred to as OR).
, 14 is Noah Gate (hereinafter referred to as NOR), 15.1
Reference numeral 6 denotes a switch composed of an FET or the like, which is turned off when the control signal is at L level and turned on when the control signal is at H level.

19 is a photodiode located near the Xe discharge tube to detect the amount of light emitted from it; 17, 18, and 20 are a capacitor and an operational amplifier, respectively, constituting a known optical integration circuit a. 21
is an A/D converter with a comparator connected in parallel, 2
2 is a latch circuit, 23u D/A converter, 24 is a comparator that compares the output of optical integration circuit a and the output of D/A converter 23, 25 is an AND gate (hereinafter referred to as AND), 26 is 0R127 is an inverter, 28 is capacitor, 29 is a diode, 30 is a resistor, 28, 29
．． 30 is a differentiating circuit that detects the falling edge of a pulse. 31 is AND, 32 is a monotable multivibrator (hereinafter referred to as one-shot O8), and 33 is AND
.

34 is an inverter, 35 is an AND, and 36 is an FL8 F/F with a clear function that is set when a signal to start pre-emission is input from the B terminal.

37. 38.40 is the inverter, 39.41 is the OR,
42, 4, 7 are AND, 43, 44.45 are capacitors 28. Resistance 30. It is the same as the diode 29 and constitutes a differentiating circuit. 46 is a comparator that detects whether or not voltage is applied to the E terminal, 48.49 is a resistor that determines the amount of current drawn from the E terminal to the strobe circuit side, and 5o is the front curtain switch of the camera by switching the resistor 48. This is a switch for switching between synchro mode and rear curtain synchro mode; when it is off, it switches to first curtain synchro mode, and when it is on, it switches to rear curtain synchro mode. 51 is a transistor that turns on when the comparator 7 is at H level (charged); 52 and 54 are resistors; 53 is a transistor that turns off the transistor 51; 55 is a mode changeover switch that switches between EFLK mode and TTL dimming mode. be.

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, when the flash light amount is set to be 17N of the main light emission amount, the capacitance of the capacitor 4 is set to be 1/N of the sum of the capacitance of the capacitor 4 and the capacitance of the capacitor 56. be done. Therefore, for example, the pre-flash amount is 1/1/1 of the main flash amount.
In the case of lO, the capacitance of the capacitor 4 is set to be 1/9 of the capacitance of the capacitor 56.

57 and 58 are backflow prevention diodes, and 59 is a switching element 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. It is. Due to the switching element 59, light is emitted using the energy stored in the capacitor 4 during pre-light emission, and light is emitted using the energy stored in the capacitor 4 and the capacitor 56 during main light emission.

Further, the capacitances of the capacitors 17 and 18 of the optical integration circuit a are set in the same manner. The A-F terminal is the terminal that connects to the camera.
The A terminal is an X contact, and the B terminal is a terminal into which a signal to control the start and end of pre-flash is input from the camera side. When the signal input to this terminal is reversed from H level to L level, the strobe device starts pre-flash, When the level is reversed from L level to H level, light emission ends. The C terminal is a terminal that transmits a photographing mode signal set on the strobe device side to the camera side, and when it is at H level, it is in EFLK mode, and when it is at L level, it is in TTL light control mode. When an H level signal is input to the D terminal, the strobe device will emit light even if the signal at the X contact changes from H level to L level until the signal input from the D terminal is inverted from H level to L level. In the TTL dimming mode, the signal input from the D terminal is inverted from L level to H level, thereby stopping strobe light emission. The E terminal is a terminal to which a constant voltage applied from the camera side is input, and depending on the amount of current flowing through the E terminal, the camera's front curtain sync mode,
The F terminal, which is determined by the trailing curtain synchronization mode, is grounded.

Second part about the operation of the strobe device configured as above.
This will be explained using the time chart shown in the figure.

First, a case will be described in which the EFLK mode is selected by the switch 55, the C terminal is at H level, the switch 5° is off, and the front curtain synchronization mode is selected.

When the switch 2 is turned on and the voltage of the main capacitor 4 increases by the DC/DC converter 3, the comparator 7
The output of is inverted from L level to H level. As a result, the LED 9 lights up and the transistor 51 turns on (as shown in the time chart t1).

After that, when the first stroke of the camera's release button is turned on at the timing shown in the time chart t2, 8W1 of the camera, which will be described later, is turned on and a constant voltage is applied to the E terminal.
A specified current flows through the resistor 49. In this case switch 50
is off, so the current flowing to the E terminal is, for example, 200μ.
A is relatively small. After that, when the switch 8W3 on the camera side for performing pre-flash, which will be described later, is turned on,
As shown in step≠8゜≠22 of the flowchart described later, the signal at the B terminal rises to the H level, the photometry for the outside light is performed, and then the signal at the B terminal falls to the -HL level (time cheat). (shown in 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 10 as a rising signal via the AND35.0R13, and the energy of the capacitor 4 causes the Xe discharge tube 11 to Light emission occurs. At the same time, the output of the NOR 14 becomes L level, the switch 15 is turned off, and the optical integration circuit a starts to operate and starts to integrate a part of the amount of light emitted from the Xe discharge tube 11. At the time of t+octopus, the switch 16 is off, so the integration circuit a
The integrating capacitor 18 is connected to the feedback loop of the operational amplifier 20 only with a small capacitance capacitor 18. Simultaneously with the start of such integration, the P/F 36 is set similarly to the trigger circuit 10, and the Q output is inverted to L level and the Q output is inverted to H level.

The light reflected from the subject 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. 4a, and when it reaches a predetermined level, the signal at the B terminal changes from the L level to the H level. Invert (t4 shown in FIG. 2). The rise of this signal causes inverter 27. capacitor 28
．． Diode 29. A rising pulse is generated in a differentiating circuit consisting of a resistor 30, and is passed through 0R26 to a control circuit 12.
input, the light emission of the Xe discharge tube 11 stops, and
It is input to the clock input terminal of the latch circuit 22. A/D
The converter 21 constantly A/D converts the integrated value of a portion of the amount of light emitted by the Xe discharge tube, and the result is latched into the latch circuit 22 when the light emission of the Xe discharge tube stops. 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 during the pre-flash when the level of the incident light reaches a predetermined level is stored in the latch circuit 22. That will happen.

The case where the second stroke of the release button of the camera is then pressed and the switch SW2 shown in FIG. 4a is turned on will be described. First, before the shutter runs, DJ
The child's signal is rising. When the shutter runs, the front curtain of the shutter completes its run, the X contact turns on, and the terminal A goes to L level (time chart). The output becomes H level, and the output of 0-832 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. Also, in this case
The contact is turned on, the switching element 59 is turned on, and the energy from the capacitor 56 and the capacitor 4 causes the Xe discharge tube to emit light. At the same time, the output of AND42 also becomes H level, turning on transistor 53.
1 is turned off, 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 loosely connected in feedback of the operational amplifier 20 of the optical integrating circuit a is the sum of the capacitances of capacitors C17 and C18. Further, the output of the optical integrator circuit a while the Xe discharge tube 11 is emitting light is input to the comparator 24, and compared with the output of the D/A converter 23. If they match, the output of the comparator 24 is inverted from L level to H level, and AND25, Enter. Here, as mentioned above, the Q output of the F/F 36 is at H level and the switch 55 is selected to the EFLK mode, so the AND2
The output of the Xe discharge tube 11 becomes H level with the inversion of the output of the comparator 24, and is inputted to the control circuit 12 via the 0R26, and the light emission of the Xe discharge tube 11 is stopped. In this case OR39
Because the output of is L level (Q of F/F36 is L level,
The output of the inverter 38 is at L level), and the output of AND 47 is also at L level. Therefore, even if the light emission stop signal is output from the D terminal, the capacitor 43. Even if a positive pulse is output from the resistor 44° diode 45, the output of the AND 47 is always at the L level and cannot be accepted. In other words, when the strobe device is in EFLK mode, the camera is
It has a function of outputting a light emission stop signal to stop the strobe light emission of the TL flash control, and even if the light emission stop signal is output from the camera during strobe light emission, the strobe light emission will not be stopped by the signal.

Also, the time chart from 111 to t1 shown in Fig. 2 is for the case where the strobe device is set to BFLK mode by the switch 55 and the release button is pressed to the second stroke without pressing the pre-flash switch on the camera side.
This will be explained with reference to 6.

If you press the release button to the second stroke without pressing the pre-flash switch on the camera side, no signal will be input to the strobe device from terminal B, so F
/F 36 is not 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. The pulse signal generated in the i-anti-44° diode 45 is input to the control circuit 12 via the AND47.0R26, and the light emission of the Xe discharge tube 11 is stopped.

Therefore, the strobe device is set to E F by switch 55.
Even in the LK mode, if the camera side does not pre-flash, the strobe light emission is stopped by a light emission stop signal from the camera side, so that proper exposure can be obtained.

Further, the pTTL dimming mode is selected by the switch 55,
A case will be described in which the C 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 pre-flash switch is pressed on the camera side, the B terminal is inverted from H level to L level. Even if a signal is input, the signal is not input to the trigger circuit 10. Therefore, it is important that light is emitted.

If the release button is still pressed to the second stroke, the above-mentioned strobe device is set to EFL by switch 55.
This is the same as when the K mode is set and the release button is pressed on the second stroke 1 without pressing the pre-flash switch on the camera side.

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

When the switch 50 of the strobe device is turned on, the resistor 48 is inserted in parallel with the resistor 49, and the impedance of the E terminal when viewed from the camera side becomes small. Therefore, if a low voltage is applied to the E terminal, the current flowing from the camera side increases, and it is detected on the camera side that the rear curtain synchronization mode has been selected. In rear-curtain synchronization, as will be described later, unlike normal (first-curtain synchronization mode), the camera holds the D terminal H until just before the shutter rear curtain starts running.
level (in front-curtain sync mode, D
The terminal is inverted from H level to L level just before the shutter front curtain travels (see steps -+229 to +232 of the P-chart described below), so even if the shutter front curtain completes travel and the X contact is turned on. Even if the signal at the A terminal changes from the I-■ level to the L level and one of the inputs of the AND33 goes through the inverter 33 to the I] level, the output of the AND33 remains L until the signal at the 10 terminal is inverted to the L level. It remains at the level and no signal is input to the trigger circuit 10.

Since the signal at the D terminal is inverted from H level to L level just before the shutter trailing curtain starts running, the signal is synchronized with the inversion of this signal [7
Then, a signal is input to the trigger circuit 10, and a strobe light is emitted. The other operations are the same as those in the front-curtain synchronization mode, so explanations will be omitted.

Therefore, the shutter time is longer than the strobe synchronization time.
When trying to photograph a moving subject using so-called slow synchronization, in front-curtain synchronization mode, as shown in Figure 3a, the subject (car) will be properly photographed by the strobe light at the position where the subject (car) starts moving when the front curtain of the shutter completes travel. photo,
At time 1 when the shutter trailing curtain starts running, the subject appears in an undertone as shown by the dotted line. In other words, even though the subject was moving in the direction of the arrow shown in Figure 3a, some photographs gave the impression that the subject was moving in the opposite direction, but in rear-curtain sync mode, As shown by the solid line in Figure 3b, the subject appears properly at the moving position when the shutter trailing curtain starts moving, and before that, as shown by the dotted line, the subject appears undertone, giving the impression that the direction of movement of the subject is appropriate. You can get photos.

Next, a camera used with the strobe device shown in FIG. 1 will be explained using FIGS. 4a to 12.

First, the hardware of this camera will be explained using FIGS. 4a to 4C and FIGS. 5a, 5b, 6a, and 6b.

FIG. 4a is a block diagram of the control circuit for such a camera. In FIG. 4a, cc and cc are voltages supplied from a power supply circuit (not shown).

60 is a microcomputer (
It is a one-chip type (for example, Motorola 6805) that has a built-in CPU (hereinafter referred to as CPU), ROM for programs, and RAM for memory. 61-A is an 8-bit parallel address bus (hereinafter referred to as AD), and 61-D is an 8-bit parallel data bus (hereinafter referred to as DB). 62°7
1.80 is a 3-state pass buffer, and switches 63 to 70 input the encoded ISO sensitivity apex value using switches provided on an ISO sensitivity setting dial (not shown). Switches 72 to 79 are switches provided on the lens mount (not shown) and are used to open the lens FNO.
wo: Enter the apex value converted to '-. switch 8
1 to 88 are aperture and shutter speed setting dials for inputting a set aperture value and a set shutter speed. A decoder 89 decodes the signal on the address bus 61-A of the CPU 60, selects one of the outputs C80 to C88, and sets it to H level, and sets the remaining outputs to L level. 90 is an A/D converter, and 91 is a D/A converter, which is configured to output a voltage of VC-18 mV×N in response to an input of a digital value N. 92 to 97 are elements constituting a light control circuit for performing TTL light control on the camera side.

92, as shown in FIGS. 4B and 4C, which will be described later, when the quick return mirror 408 is down, light is transmitted through the sub-mirror 409 and the half mirror at the center of the mirror 408, and the light is measured at the center of the subject. , mirror 408
The light receiving element, the diode 93, and the operational amplifier 94, which are configured to measure the light reflected from the film surface when the shutter is open and the shutter is open, are a known logarithmic compression circuit, and the base of the transistor 95 is the operational amplifier 94. NPN whose emitter is connected to the D/A converter 91 and whose core is connected to the capacitor 96.
) A transistor used for expansion. 97 is H
This is a switch that is turned on when a level signal is input, and is a capacitor provided in parallel with the 96# switch 97.

In order to make the following explanation easier to understand, the operation of such a dimming circuit will be briefly explained.

The output V94 of the operational amplifier 94 can be expressed as follows, assuming that the photocurrent generated by the light incident on the tri light receiving element 92 is 1 spc.

In addition, the output voltage of the D/A converter is set to VC' as mentioned above.
-18mV
m V

The collector current ICE of the transistor 95 is integrated by the capacitor 96 even after the switch 97 is turned off.

Therefore, after t after the switch 97 is turned off, the collector voltage of the transistor 95 becomes H. 98.9
9 is a constant voltage source and a comparator, respectively, and when the voltage at the connection point between the collector of the transistor 95 and the capacitor decreases from Vcc through integration and becomes lower than the output voltage EFref of the constant voltage source 98, the voltage changes from L level to 1 ( By inverting the level, it indicates that the charge accumulated in the capacitor 96 has reached a certain amount, and constitutes a circuit that stops strobe light emission.This circuit also transmits a light emission stop signal to the flash device shown in Fig. 1. Output.

The output of the D/A converter 91, the capacity of the transistor 96, and the voltage of the constant power supply 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 receiving element 92 is Q, l 1ux-sec
The capacitance of the capacitor 96 and the constant voltage source 98 are set so that the light emission stop signal is output from the comparator 99 when the amount of light (corresponding to the appropriate exposure amount for an ISO 100 film) is incident.
As mentioned above, the current between the collector and emitter of the transistor 95 in the dimmer circuit will double every time the output of the D/A converter 91 changes by 18 mV. When the output is V-18mV, it is 0.21LIX -see and V+18m
When the voltage is V, a light emission stop signal, which is the output of the comparator 99, is output at 0.051 ux-sec. A resistor of 100 to 102 and an operational amplifier 1o3 constitute a circuit that inverts and amplifies the collector voltage of the transistor 95. 104 is a light receiving element that measures the peripheral part of the frame, 1o5 is a light receiving element that measures the central part of the frame, 1
o6 is an electrical switch, 107 is an operational amplifier, 1
08 is a diode, and 107 and 108 constitute a known logarithmic compression circuit.

When the switch 106 is open, a logarithmically compressed photometric value of the brightness at the center of the field is outputted from the operational amplifier 107. When the switch 106 is closed, 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 is output. Resistors 109 to 111 and operational amplifier 112 constitute an inverting amplifier circuit. 113 and 114 are electrical switches;
An inverter 115 selects the input to the fi A/D converter 90 based on the signal from the CPU port P21. 116 is a magnet for releasing the first tension of the camera and starting the mechanical release sequence);
, 118 activates automatic throttling when energized,
120 is a magnet that causes the front shutter curtain of the camera to run; 122 is a magnet that causes the rear shutter curtain of the camera to run; 117; ．． 119
, 121 and 123 are transistors for energizing the magnet. Reference numeral 124 denotes an X-connection switch that changes from off to on when the front curtain of the shutter finishes running, and from on to off when the rear curtain of the shutter starts running. 125
, 126 is an or gate.

127.1'29 is a resistor, 128 is an operational amplifier, 130
is a transistor, and when the transistor 130 is on, the voltage of the E terminal is grounded, and when it is off, the voltage of VC is applied, and at the same time, the E terminal is connected 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 reference voltages for comparators 134 and 135. 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 13 is set so that the output of the comparator 134 becomes H level due to the flow of a larger current (for example, 800 μA).
A resistance value of 1 to 133 is set.

Reference numeral 136 denotes a power-up clear circuit (hereinafter referred to as PUC circuit) which outputs an L level for a certain period of time when the power is turned on from a power supply circuit (not shown), and then outputs an H level.

SWl 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 that does not cause pre-flash, and SW4 is a switch that is turned on when winding is completed. SW5 is a switch that is turned off when the mirror shown as 408 in FIGS. 4B and 4C is raised. SW5 is a switch that is turned on when the trailing curtain is completed and turned off during winding. SW6 is a switch that switches between partial metering and average metering. SW7 is a switch that turns off when the mirror is raised. SW8 is a switch that repeatedly turns on and off in accordance with the amount of aperture tightening so as to output one pulse each time the aperture is narrowed down by one step in synchronization with an aperture member (not shown).
S'W9 is a switch for resetting the information obtained by pre-flash in LK mode.S'W9 is a switch for switching between aperture-priority shooting and shutter-priority shooting.When it is on, shutter-priority shooting is used, and when it is off, it is aperture-priority shooting. Shooting is selected.

200 is a display unit that displays information using an LCD; 300 is i;
This is a display unit that performs display using EIf).

Figures 4b and 4C are cross-sectional views of such a camera, with Figure 41) showing a state in which the mirror is lowered, and Figure 4C showing a state in which the mirror is raised.

In FIGS. 4b and 4C, the elements shown in FIG. 4a are designated by the same reference numerals and their explanations will be omitted.

In Figures 4b and 4C, 401 is a camera barrel, 40
2 is a photographing lens, 403 is a film, 404 is a shutter, 405 is a pentaprism, 406 is an eyepiece lens, 4
07 is a focusing glass, 408 is a half mirror, 1409 is a sub-mirror attached to the center of mirror 408, 41
0 is a secondary imaging lens, 92 is a light control sensor shown in Fig. 4a, 104 is a light receiving element for average photometry, 105 is a light receiving element for partial photometry, and in Fig. 1.4a is the light passing through the lens. is reflected by a mirror 408, converted into an erect image by a pentaprism 405, focused on a focusing glass 407, and observed by the photographer through an eyepiece 406.

Numerals 1, 04 and 105 are elements that receive and measure the diffused light within the pentameter, each of which measures two parts on average. With the camera configured as described above, when the mirror is down, the central part of the light hitting the nof mirror 408 passes through the mirror 408 and is reflected by the sub-mirror 409, and passes through the secondary imaging lens 410 to the light receiving element. 92.

Next, when shooting is started and the mirror 408 is raised, the light receiving element 92 measures the light reflected from the entire film surface.
In other words, the entire film surface is averagely measured.

FIG. 4d is a diagram showing the display in the viewfinder of the camera shown in FIGS. 4a to 40, and the viewfinder is displayed by the LCD display section 200 DEG display section 300 shown in FIG. 4a.

In FIG. 4d, reference numeral 407 indicates a focusing glass visible through the finder. 412 is a micro split prism. On the right side of the focusing glass, there is an LCD display section 200.
The LCD display is caused by this. At the bottom of the focusing glass, an LED display section 300 displays the shutter speed and aperture value. Furthermore, the range that can be seen in such a finder is 4a.
This corresponds to the frame described for the light receiving elements 104 and 105 in the figure.

Next, using FIGS. 5a and 5b, the LCD display section 200
, 6a and 6b, the LED display unit 300 will be explained.

FIG. 5a is a circuit diagram of the LCD display section 200, and FIG. 5b is a circuit diagram of the LCD display section 200.
, is a diagram showing the arrangement of display elements of the CD display section 200.

In Figures 5a and 5b, El ~E29゜MO~M
29 are liquid crystal elements arranged in rows to indicate whether the strobe light emission amount is appropriate and whether the set shutter speed and aperture value are appropriate for external light, as shown in Fig. 5b. It is arranged in a form.

In addition, in this figure, if M2S and El5 are % steps under from proper exposure at a position indicating proper exposure, M14. If El4,3A stage is over, M
16. Display is performed in units of % so that El6 is driven.

201 and 202 are latch circuits, and the data bus 61-
Write signal WR for 8 pit data of D.

This is a circuit that reads and holds the signal by AND with the chip select signal C85 or C86. Decoders 203 and 204 decode the 8-bit data latched in the latch circuits 201 and 202 to set only one output to H level and the rest to L level, and also to set the data latched in latch 201 to 0. In some cases, the O output is at the L level, and in other cases, the 0 output is at the H level. 2
05 is a clock generation circuit for generating clock pulses for liquid crystal display, 206 to 264 are exclusive OR gates, and 265 is an inverter. Here, liquid crystal M1 to M
29, when the outputs of the decoders 203 and 204 are at H level, the voltages applied to both ends of B1 to g29 turn on as pulses are in opposite phases to each other, and when they are at L level, they are in phase with each other, so they are turned off. Therefore, latch circuit 201
, 202 are both O, all the liquid crystal elements are turned off, and in other cases, the liquid crystal elements selected by the scale display and latch circuits 201 and 202 indicated by MO are turned on one by one. Further, the protrusions appearing on the right side of the scale display indicated by MO are provided at each step deviated from the proper exposure indicated by >.

FIG. 6a is a circuit diagram of the LED display section 300, and FIG. 6b is a circuit diagram of the LED display section 300.
3 is a diagram showing the arrangement of display elements of an ED display section 300. FIG. 3
01 and 302 are latch circuits that convert the 8-bit data of the data bus 61-D into the write signal WR and the chip select signal C.
Read and hold with the AND of 83 and C84. A decoder 303 decodes the shutter time data latched in the latch circuit 301 and displays the shutter time on the seven segment LEDs T1 to T4. In addition, the LEDs configuring LED T1 to T4 (7 segments) each have a resistance of 305 to
332 to the power supply.

For example, if the data latched in the latch circuit 301 indicates a shutter time of 1/60, T3al
T3clT3dlT3elT3flT3gIT4aIT
4b, T2Or T4d * T+e + T4f
The decoder 303 operates so as to turn on the light, turn off the other lights, and display h, j j.

Further, when the data of the latch circuit 301 is oo, Tla
- All T4g lights go out. Further, the decoder 304 decodes the aperture value data latched in the latch circuit 302 and displays the aperture value on the 7-segment LED AIA2. In addition, LED A1 a-Azg and Adp that constitute 7-segment LED A and A2 each have a resistor of 3.
33-346 and 347 to the power supply.

For example, if the data latched in the latch circuit 302 indicates an aperture value of 12, A, tb
, AIC, , A2B, A2b, A2d , A26 , A
zg.

The decoder 304 operates so that 1.8 is displayed by lighting up Ad and turning off the others. Furthermore, when the data in the latch circuit 302 is 00, Ala-A4B and Adp are all turned off.

Next, the operation of the microcomputer that controls the operation of the camera shown in FIG. 4a will be explained using the flowcharts shown in FIGS. 7 to 12.

In the above flowchart and its explanation, for the sake of clarity, the address bus 61-A shown in FIG.
AB, data bus 61-D to DB, ISO information setting switches 63 to 70 to 1sop, lens open FNo.
Switches 72 to 79 provided on the lens mount section to read the AVOP, switches 81 to 88 to set the aperture or shutter speed, ATP, LcD, latch circuits 2o1 and 2o2 to latch the data for display, respectively, for MBARP1EBARP1 and LED display. Of the latch circuits 301 and 302 that latch the data of
The latch circuit 302 that latches the aperture data is AVDP.
, the AD converter 90 is referred to as ADP%, and the DA converter 91 is referred to as DAP. In addition, when providing an explanation, it may be written without abbreviations to aid understanding. Also AV, TV.

Sv, Bv, Avc, Avo, EF, AVNEW, TV
NEW, TvMIN.

TVMAX and EF ref are the aperture value, shutter time, ISO sensitivity, subject brightness, lens aperture value, pre-flash received light amount, calculated aperture value, calculated shutter time,
Lowest speed shutter time, highest speed shutter time, constant voltage source 9
A data register of the value obtained by AD converting the output voltage of 8, T
IMERF and CCCF are respectively flags that are set to 1 when the timer circuit-TIMER in the CPU 60 finishes counting time, and flags that are set to 1 when BEFL and mode are selected and pre-flash is performed, as shown in the flowchart below. The operation of the microcomputer in the steps indicated by the numbers with a "+" will be explained. First, the steps shown in the flowchart and the instructions in those steps will be clearly stated, and then the microcomputer in the steps and the instructions in step 4a will be explained. The operation of the entire camera shown in the figure will be explained.

Film winding is completed, switch SW5 is on, input capacitor P5 is at L level, power switch 42 of the strobe device shown in FIG. 1 is on, and capacitor 4 is turned on.
The operation will be described when the BPLK mode is selected by the dead mode changeover switch 55, which has completed charging, and the switch 50 is off and the front curtain synchronization mode is selected.

+1; First, when a power supply voltage is applied by a power supply circuit (not shown), the PUC circuit shown in FIG. 4a turns on the CPU 60.
When the reset terminal of is set to L level, the CPU 60 writes all output ports to L level and writes 0" to all registers.

42: TVDP←00)I Indicates that a hexadecimal number (7) “0” is output to the Kono instruction 1 TVDP port. Note that I( is a code indicating that it is a hexadecimal number. With this instruction, the CPU 60 outputs 001() to the address of the address bus A I3 K T V I) P, for example, 43H1 data bus]) H. Afterwards, the write terminal VR is pulled low for one fixed period of time.Therefore, the decoder 89 causes C83 to go high, and the other CSOs.

Outputs low to C8I, C82, C84, and C88. Therefore, latch circuit 301 is selected, and latch 30
Only 1 can receive data 00H on data bus DB. The latch 301 receives the received data OOH.
is held and output to the decoder 303, and the decoder 303 decodes the data and displays the shutter time display LEDT1a-T.
4g is displayed, but there are O and O in the latch circuit.
Since I-I was output, the decoder 303 turned on the LED T1a.
=Turn off all T4g lights.

+3: AVDP←00■I Just like +2, 00H is output to the latch circuit 302 to turn off the aperture value display LEDA1a-A2f and Adp.

+4: EBARP 4-00H ≠5: BBARP←0OH Similarly, OOH is written in the latch circuits 201 and 202 of the LCD display circuit 200 for 44 and 45 to erase all the display on the LCD.

+6: P4O10 This command indicates that the output of port P19 is set to the high level. This turns on transistor 1'30. Here, as shown in FIG. 1, the E terminal of the strobe device is connected via a resistor to the input terminal of the comparator 46 and the emitter of the transistor 51 whose emitter is connected to the ground, so the output of the comparator 128 is falls close to the ground, and the E terminal also becomes low level, so the output of the comparator 46 becomes low level and the latch circuit 22 of the system strobe device is cleared.

+7:P3'? This command indicates that the state of the input capacitor P3 is to be determined. Here, if the pre-flash switch 8W3 is off and P3 is high, the pre-flash switch 8W3 goes to +16.
If it is on and low, branch to +8.

Here, it is assumed that the pre-emission switch 8W3 is not turned on, and the process proceeds to +16.

I#+16:P1? Similar to +7, this command indicates that the state of the switch SWI, which is turned on by pressing the first stroke of the release button, is determined from the input capo-PI.
If the stroke is not pressed, go to ≠2; if not, go to ≠17. Therefore, if both SWI and SW3 are turned on now, +2 to +7. =lI-1
It happens that the loop of 6 keeps repeating.

At this point, the photographer places the main subject in the center of the viewfinder and presses the pre-flash switch SW to perform a pre-flash with the memory type flash control.
When 3 is turned on, it branches to ≠8.

+8:P19←0. P15←1. P16←1 By executing this command, the transistor 130 is turned off to output an L level to the port 19, and the operational amplifier 128 operates to set the voltage at the E terminal to VC. At the same time, PI3.
By setting PI3 to I-(level), the B terminal CM1 shown in FIG. 4a is set to H level and strobe light emission is prohibited.

N9: P18'i' Determine the state of input port P18. Here, when the capacitor 4 of the strobe device shown in FIG. 1 is fully charged, the transistor 51 is on, so a constant current (for example, 250μA), so the output of the operational amplifier 128 is VC+R12gX250/jA (R1
(28if: resistance value of the i resistor 128) Therefore, the output of the comparator 135 becomes H level, and the CPU 60 can detect whether the strobe device is fully charged. Here, even if the rear curtain synchronization and front curtain synchronization are selected with a high shutter power by the switch 5° on the strobe device side, when the strobe device is fully charged, the output of the comparator 135 becomes H level.

As explained at the beginning of the flow, since the strobe device is fully equipped, control moves to step 10.

≠10:P14'? This is a command to determine the state of the input port 14. The mode changeover switch 55 of the strobe device shown in FIG.
mode. As explained at the beginning of the flow, the switch 55 is at H level because the EFLK mode is selected. Therefore control is +1
Move to 1.

41+11- Subroutine Pre-flash This subroutine fires the strobe pre-flash before shooting.
This is a subroutine that determines the amount of strobe light emission during photographing according to the reflected light from the subject. A detailed flowchart is shown in FIG.

First, prior to pre-emission, a flow is executed to determine the aperture value and shutter time based on external light and the aperture value or shutter time set at the ISO sensitivity.

The pre-emission subroutine will be explained below with reference to FIG.

+ 101: Sv 4- I 80 P This command indicates that the I80 sensitivity is read from the register and the star Sv from l5OP. When j5cPU60 outputs OOH to address bus AB by this instruction, decoder 89 outputs C8o.
Switch 6 to set the I80 sensitivity to set it to H level
3 to 70 bus buffers 62 are selected. Next, the RD terminal is pulled down to L level for a certain period of time. Therefore, the path buffer 62 selected by the decoder 89 outputs the data of the switches 63 to 70 to the data bus DB. C.P.
U60 reads the DB data at the rising timing of the L level signal output to the RD terminal, reads the set ISO sensitivity, and stores it in the read register SV.

+102: AVOn-AVOP This command indicates that the maximum aperture value of the lens is read from AV OP into the register AVO, and the same operation as ≠101 is performed.

+103:P9? This is a command for determining the state of P9 (input capo), and it is determined by this command whether shutter priority photography or aperture priority photography is set. When the switch 8W9 is on, the shutter priority shooting mode is set, so the process branches to ≠104. When the switch 8W9 is off, the aperture priority shooting mode is set, so the process branches to ≠115.

First, a case will be described in which the photographic priority shooting mode is set.

+104: TV4-A'l"PThis command is A
, TP indicates that the shutter time is read into the TV register, and the same operation as +101° +102 is performed.

+105: 'I'V: 1/250 This instruction is a comparison instruction between the contents of the register Ty and the strobe synchronization time of 1/250. When the set shutter time is faster than the strobe synchronization time, for example 1/250 seconds, executes +106 command, and when it is slower than the strobe synchronization time, +107 is executed.
Execute.

$106: Ty←1/250 This command sets the strobe synchronization time to register TV to 1/250.
By substituting data corresponding to seconds, the shutter time will not exceed the synchronization time during flash photography. If the set second time is slower than 1/250, this command is ignored by +105 and exposure is performed at the same second time.

+107:F20←l;F21←l This command outputs an H level signal to F20, closes the switch 106, and leaves the switch still open)f'
21 to close the switch 113 and open the switch 114. The camera is in the state shown in Fig. 4b, and the second stroke of the release button is turned on.
02, the object is reflected by a mirror 408, made into an erect image by a pentaprism 405, and observed by the photographer through an eyepiece lens 406.

In this state, 1,000 parts of the subject light is still on the light receiving element 104.
, 105 as well. Further, as explained in FIG. 4a, the light receiving element 104 is set to receive light from the peripheral part of the frame, and the light receiving element 105 is set to receive the object light from the central part of the frame.

Therefore, by executing +107 switch 1
06 is closed, the light receiving elements 104 and 105 are connected in parallel, and a logarithmic compression circuit composed of an operational amplifier 107 and a diode 108 outputs a logarithmic compression value of the average photometric luminance of the entire frame.

As explained in FIG. 4a, the output of the operational amplifier 107 is inverted by the operational amplifier 112 and the resistors 109 to 111, and the gain and level are adjusted. 90.

+10'8: By 4- AD The PCPU 60 reads the output of the A/D converter 90 into the register BV. In this case, the data read into the register BV is a value obtained by AD converting the luminance data of the light incident through the open aperture of the lens of the light receiving elements 104 and 105.

+, 109: Ev E Bv 10 Sv 10 AV.

This instruction indicates to add the data of registers Bv and register Sv and register AVO and store it in register EV. Therefore, the film sensitivity and the aperture F number are added to the photometric value.

4110:Ay←Ey=Ty With this command, the data in register Ev is changed to register TV.
This indicates that the data is subtracted and stored in register AV. Subtract the shutter speed data from the Ev value to obtain the aperture value data.

4t-111: Av: AVO + 112: Av4-AvQ If the calculated comparison value obtained by executing 4111.4P112 as follows≠110 is an F number smaller than AVO, the data in register Av is The data is based on the maximum aperture value.

+113:Ay:F22=ll-114:AV←F'22+, 113. By executing ≠114, if the aperture value obtained by ≠110 is larger than the minimum aperture, for example F'22, the data corresponding to the minimum aperture of F22 is stored in register A.
Store in V.

By executing ≠104 to +114 as described above, the aperture value in the shutter priority shooting mode is determined and stored in the register AV.

Next, a case will be described in which the aperture priority shooting mode is set when the switch SW9 is off at +103. In this case, +115 is executed after +103.

+115: Ay+-ATP Load the data of IATP into register AV. Furthermore, this command gives +1
In 04 aperture priority shooting mode, switches 81 to 88
The data is read in as an aperture value signal.

+116:Ay:Ay□ +11.7: AV4-, A, y□This command is +1
Just like 10.8111, when the set aperture value is an F number smaller than the open aperture value, this is a command to set the aperture to the open aperture value.

+118: Ty 4-17250 This command is +1
Like 06, this is a command to set the shutter time to the synchronized time.

As described above, by executing steps +115 to + and 118, the shutter speed and aperture in the aperture priority shooting mode are determined, and the registers TV are respectively set.

Stored in AV. With shutter priority, both external light and the main subject are appropriate. During daytime synchronized shooting, you can still shoot with a flash at your desired aperture setting.

+ 1 1 9: D A P 4--8V + (A
Y Ay□ ) 10Kt DA converter 91 shown in FIG. 4a
In other words, 1 to 8V + AV to AVO to the DAP port.
(K1 is a constant) The D/A converter 91 outputs a voltage of pVC-(-8y+AyAyO+1)×18 mV based on the received data. The arithmetic expression and the constant 1 will be explained in detail in +122.

4120:P22←1 This command indicates outputting an H level signal to P22. This instruction causes the switch 97 shown in FIG. 4a to
is closed to short-circuit both ends of the capacitor 960.

≠121: WAIT Turn on the switch 97 to wait for the time period for the capacitor 96 to be discharged. capacitor 9
6, the inverting input of the comparator 99 becomes VCC, and the comparator 99 outputs an L level signal.

Therefore, the input of 121126 becomes L level.

+122: P15←Q, P22←O By outputting an L level signal to port 1-P15 by this command, the B terminal goes to L level and falls (in addition, when 4=8, PI3 is I] level and previously )
. As described above, the strobe circuit detects the fall of the signal at the B terminal and starts preliminary light emission. The emitted strobe light is reflected by the main subject, and the reflected light passes through the photographing lens 402, passes through a part of the half mirror of the mirror 408, is reflected by the sub-mirror 409', and is focused by the lens 410, as shown in FIG. 4b. The light then reaches the light receiving element 92.

At the same time, P22 becomes O and integration starts. In that case,
The amount of light incident on the light receiving element 92 is determined by the half mirror 408,
The amount of light is lost due to the lens 410 and the like, and is less than that on the film surface.

For the sake of clarity, it is assumed here that the amount of light incident on the light receiving element 92 is 1/8 of the amount of light incident on the film surface due to the aforementioned light amount loss.

Further, as explained in the strobe circuit shown in FIG. 1, the preliminary light emission amount is 1/10 of the main light emission amount. Further, during preliminary flashing, the metering is performed at full open metering, but during main flashing, light is emitted after the aperture is closed down, so that more light by 2Av-Avo is irradiated onto the light receiving element 95.

Here, the appropriate exposure amount for ISO 100 film is 0, 11
Since it can be approximated as ux-see, ISO100 is converted to an apex value Sv of 5, so the appropriate exposure amount for a film whose apex value is SV is 0.1 lux.
-sec X 2 (S-8v).

In order to output a light emission stop signal at 1/10 of the proper exposure amount during main light emission during pre-light emission, the light amount loss is 1/8 as described above, so the collector current of the transistor 95 is as follows.
For the photovoltaic current ■ spc of the light receiving element 92, 1 co = 2 (5-8 inches x 2 (AV + AvO) x 8
x 10 x l5PC: 2 (5-8v+AV-Av
o+3+332) It is necessary to flow a large amount so as to satisfy the relationship of XIsPc.

Therefore, the output of the D/A converter 91 is VC-
18mV X (5-8y +A, y-A, yO+6.
32) If 1 is set to 1132, a digital value corresponding to -8v+AV-AvQ+ is input to the digital input N of the D/A port.

Since the above conditions are satisfied by executing steps 41 and 19, when the preliminary flash is performed, the comparator 99 is turned on when the subject emits a light amount of 1/1O, which is the proper exposure when the main flash is performed. , the signal at the terminal B rises from the L level to the I (level), and the preliminary flash of the strobe can be stopped as explained in FIG.

+123: WAIT By executing this command, the CPU 60 waits for a sufficiently set time until the above pre-emission operation is completed.

+124:P237 This command inputs the output of comparator 99 to input port P23.
This is a command to detect the light emission stop signal of the pre-flash by detecting the light emission stop signal from the comparator 99. If the output of the comparator 99 is 1, that is, the light emission stop signal is output, it goes to +125, and if it is 0, that is, the light emission stop signal is not output, it goes to 4-126. Execute.

≠125: BF←15 If the light emission stop signal is output, this command is executed and data 15 is used to properly display the EF register.
is stored.

$126: P21←Q, P15←1 If the light emission stop signal is not output, set L to output port P21.
Switch 113 is turned off by outputting a level signal,
Turn on the switch 114 to change the output of the operational amplifier 103 to A.
/D converter 90.

If the light emission stop signal is not yet output from the operational amplifier 99, output an H level signal to the output port P15 and connect the terminal B.
signal is raised to store the amount of light emission in the strobe device.

≠1 27: ET"+-ADP This command stores the voltage of the capacitor 96 in the EF register as a digital value obtained by A/D conversion.

4F 128: EF4-TABLE (EF) This command refers to the table TABLP on the ROM of the CPU 60 and selects 1 to 1 corresponding to the digital value stored at +127.
This is an instruction to store a value of 5 in the EF register. The value of table TABLE is stored in register EF as shown in Figure i13.
The terminal voltage of the capacitor 96 corresponding to the digital value stored in is VgF. The voltage at proper exposure is VEF'ref.
Then, when it is appropriate, it becomes vEF-VEFref, and the table TABLE returns a value of "15". Also, when the first stage is under, the strobe light is at the proper %, so the VEF
=VCC--z (Vcc-VEFref), and 1T 70''TA) 3LE returns a value of "11". Therefore, when it is proper, the contents of register EF will be "15" and 1.
If the number is under the stage, the number is "11" and the number decreases by "4" for each stage thereafter. Also, if there is no strobe light, it is vEF-VCC and the table TABL
E returns "1".

+129: EBARF4-EF This command displays the contents of register EF on the LCD display section 20.
0 IC feed, L CD display section 200 (As a result of pre-flash of the tropo, when the main flash is performed, the subject is properly displayed or how many steps under is displayed. +, As shown in 128, The contents of register EF are “
In the case of ``15'', if it is ``11'', it is one step under, and if it is ``7'', it is two steps under.

+130: TVDP4-TV, AVDP4-
AV This command sends data to the LED display section 300 to display the current shutter speed and aperture value.

≠131: RETURN The main routine shown in FIG. 7 is entered.

+12: CCCF←1 This command sets the flag CCCFKI to indicate that it is in EFLK mode. This flag is determined during exposure when the shutter is moved, and if ■ stands, the CP
U60 sets the output port P16 to the ■ level, thereby setting the D terminal to the L level and enabling the strobe device to emit light.

413 EF"LKljl11 Optical Subroutine The subroutine is a subroutine that measures and displays the outside light before exposure. This makes it easier to perform daytime close-up photography by displaying the brightness of daylight during EFLK. It is something.

The ET'LK photometry subroutine will be explained below with reference to FIG.

+151:P6? This is a command to determine the state of the input capo-1-P6, and determines the state of the photometry mode changeover switch SW6.

If it is on, it goes to +153, and if it is off, it goes to minus 152, and by switching the electronic switch 106, the photometric sensitivity distribution is changed.

Temple 152: P20←1 When an H level signal is output to the output port P20, the switch 106 is closed and center-weighted average photometry is selected.

≠153: P20←0 Output capo) When a ■ level signal is output to P2O, the switch 106 is opened and partial photometry is selected.

+ 154: P 214-1. By +-ADP
output capo) Outputs an H level signal to P21, turns on the switch 113, turns off the switch 114, converts the photometric value output from the operational amplifier 107 into a digital value by the A/D converter 90, and stores it in the register Bv. do.

41 55: MBARP4-15+4(By+5
v-Ty-Av) This command is the shutter time obtained as a result of photometry (=#, as shown in 107, the switch 106 is closed and average photometry is performed) in the subroutine preflash whose flowchart is shown in FIG. The aperture value is subtracted from the sum of the subject brightness BV and the ISO information Sv, that is, the photometric value, obtained by executing +154 for the TV and AV in which the aperture value is stored.

Note that the display is multiplied by 4 because it is displayed every two stages as explained in FIG. 5b. Therefore, if the current shutter speed and aperture value are under the photometric value, the MBA
The content of RF becomes smaller than 15, and the decoder 203 shown in Fig. 5b detects whether the current shutter speed and aperture value are appropriate for external light, as shown in Fig. 4d. The mark marks indicating proper exposure are displayed in rows so as to be located below the mark marks indicating proper exposure. In addition, if the pre-flash is performed and it is detected that the subject will hit properly when shooting with the main flash, as shown in Figure 4d, the mark indicating the result of the pre-flash will be placed at the same height as the marfre. To position. If the pre-flash is performed and it is detected that the subject will be under-shot during the main flash, the mark < indicating the result of the pre-flash will be located below the marfre. Additionally, the shutter speed and aperture value are displayed on the LED at the bottom of the viewfinder.

+15'6:P9? This command is exactly the same as the command shown in 4F103,
Determines whether shutter priority or aperture priority is used. If you want shutter priority, go to +157.

≠157: Read the TVNEW new-ATP shutter setting value.

+158: TV, i" TVNEW Determine whether the set value has changed after the preliminary flash. If you change the shutter speed after the preliminary flash, the exposure amount of the external light can be adjusted without changing the exposure amount of the system strobe. In the case shown in Figure 4d, by slowing down the shutter speed, the mark cross moves upward until it is located at the same height as the mark mark, which indicates proper exposure.
Both external light and strobe light can be adjusted appropriately.

4159: TV4-TVNEW Input T to TV register to store new shutter speed.
Transfer the value of the VNEW register.

41 6 0: MBARP 4-15+4 (By
+5y-Ty Ay) - Displays the photometric value of outside light in the same way as +155.

+ 1 6 1: Displays the preliminary flash result of the EBARP 4-EF strobe.

+1621T■1)P+-TV +163: AVI)P+-Ay Displays the shutter seconds and aperture value. Also, in the case of aperture priority, 4' 165: AyNEW+-AV+166, AV
NEW〆AV Determines whether the aperture setting value has changed. If it does not change, change to the main flow of 11g7 with +164.

+167: El! ”4--E-P+4 (Ay
-A, yNEW) In the case of aperture priority, when the aperture setting value changes, the strobe exposure amount changes. For example, if a one-stop under-display is displayed, the amount of light emitted by the strobe is memorized, and the appropriate amount of light can be obtained by opening the aperture one step. Therefore, the display indicating whether the pre-emission is appropriate will also change by the change in aperture.

+16'8: Ay+-AyNEW setting aperture is memorized. This operation allows the amount of exposure by the strobe to be adjusted freely. From then on, the display will be performed in the same way as shutter priority.

41-164: RETURN Returning to the main routine shown in FIG.

+14:P8? By determining the state of input capo P8, the state of switch SW8 shown in FIG. 4a is detected. switch SW
If 8 is on, the flow branches to +2.

Immediately, the EFLK mode is released. As a result, when executing +6, an H level signal is output to the output capo-PI3 and the transistor 130 is turned on, so the potential of the terminal E decreases and the output of the operational amplifier 46 shown in FIG. 1 changes from the L level to the H level. As a result, the latch circuit 22 is cleared. As switch SW8 continues to be turned on, the flow increases by +1.
Proceed to step 5.

+15: Switch S by determining the state of P2 (input capo)
Detect the state of W2. When the release button is pushed to the second stroke and the switch SW2 is on, +25 is executed. While the switch SW2 is off, the subroutine EFLK photometry is repeatedly executed. Therefore, the LCD display of the external light display shown in FIG. 13 changes according to the change in the brightness of the external light.

Further, the strobe exposure amount display changes according to changes in the aperture setting value. When the photographer determines that the desired aperture, shutter speed, and strobe exposure amount have been obtained, the switch SW2 is turned on when the release button is pressed to the second stroke, and subroutine exposure 4P25 is executed.

Next, subroutine exposure will be explained using FIG. 10.

FIG. 10 is a detailed flowchart of subroutine exposure.

4p201:P13←1 output capo) Outputs an I (level signal) to P13.

As a result, the transistor 117 turns on and the magnet 11
6 is energized, and the first tension of the camera is released. Therefore, an input sequence for an exposure stop (not shown) is started.

+202: P12←1 Output capo) Outputs an H level signal to PI3. As a result, the transistor 119 is turned on and the magnet 118 is energized. This is a command to perform aperture control.

≠203:WAIT Wait for the time necessary to release the camera from the first state.

4204: P13←O output capo) By inverting the output of PI3 from H level to L level and turning off transistor 117, energization of magnet 1160 is prohibited.

+205: AVC4-AV-AVO register A
The data in register AVO is subtracted from the data in V, and the data for the number of narrowing stages is stored in register AVC.

#206: AVC=O? If the register AVC is O, the program branches to +210 and executes step 210 to prohibit energization of the magnet 118 and stop narrowing down.

Na207: P7? This command determines the state of input port P7, and if switch SW7 is off and at H level, ≠20 again.
7 and wait until switch SW7 is turned on and becomes L level.

≠208: P7? This command is the opposite of -+207, and is a command to wait until the switch SW7 reaches F position and reaches the bell. Therefore +207
．． +208 is switch SW7 linked to narrowing down is 1
This is a command to wait until the diaphragm is turned on twice and the 1st stage aperture is narrowed down.

4209: After subtracting 1 from AVC+-AUC-Luxister AUC, jump to temple 206. Therefore, ≠206 to ≠209 are routines that wait for the switch SW7 to turn on and off for the number of stages of narrowing down, and when this routine is executed and the data in the register AVC becomes ``0'', +=206 causes +21.
Branch to 0.

≠210: P12←0 Output capo) An L level signal is output to PI3, the transistor 119 is turned off, the magnet 118 is de-energized, and the narrowing down operation is stopped.

In this way, the lens aperture is narrowed down to a value corresponding to the data in the register AV.

≠211:P22←1 An H level signal is output to the output port P22, the electronic switch 97 is closed, and the capacitor 96 is discharged.

≠212:P15←1 4213:P16←1 Output port P15. Output a high level signal to PI3 and raise the B and D terminals to high level.

As explained in ≠126, an H level signal is generally output to the output port P15, but ≠212 is provided in order to perform subroutine exposure without performing subroutine pre-emission.

4214: CCCF? Senses flag CCCF, CCCF is O, and EF
In a mode other than LK mode, for example, in AE mode, step 217 is executed. In the explanation up to now, CCCF is 1 and it is the EFLK mode, so the process proceeds to +226.

≠226:P17 Sense human power port 17. now strobe light ruichi 5
W50 is off and front curtain synchronization mode is set. In this case, since the strobe device draws only 250 μA from the E terminal, the input capacitor PI3 is at L level, and ≠215 is executed. Also, the strobe switch SW5
0 is on and rear curtain synchronization mode is set, when the strobe device draws 800 μA or more from the E terminal, input port Pi 7 becomes H level, +227
is executed.

≠215:P16←0 Outputs an L level signal to output port P16, sets the D terminal to L level, and sets one of the inputs of AND gate 33 to H level via inverter 40 shown in FIG. 1 to enable strobe light emission. Make it.

≠216: P22←0 Baud) Outputs O to P22. This command is to start TTL dimming, but in the BP lock mode 4, the strobe stores the amount of light emission. That is, even if TTL dimming is performed and a light emission stop signal is output, and a pulse is shown from the P terminal to the AND 47 shown in FIG. 1, it is ignored because the F/F 36 is set.

≠217: pH←1 An H level signal is output to pH, the transistor 121 is turned on, and the magnet 123 is energized to run the shutter front curtain.

4218:WAIT Time required for the shutter front curtain to start running CPU6
0 waits.

≠219: pH←O An L level signal is output to pH, the transistor 21 is turned off, and the magnet 123 is de-energized.

+220: TIMER4-TV Stores the data of register TV in the timer circuit and performs real time expansion to create shutter time.

+221: 'I'IMERF? TIME the timer flag until the shutter seconds elapse.
Continue to determine the RF status. Now, when the shutter front curtain completes its travel, the X contact 124 is turned on and the output of the AND gate 33 shown in FIG. The strobe device starts emitting light. As described above with reference to FIG. 1, the strobe device stops emitting light according to the signal from the comparator 24 after emitting the amount of light stored in the latch circuit 22 during pre-emission, so that the main subject is properly exposed. After the actual shutter time elapses, TIMIF becomes 1 CP
Execute Ul1′i≠222.

4 2 2'2 2 PIO← 1 An H level signal is output to the output port 10, the transistor 123 is turned on, and the magnet 122 is energized to run the shutter rear curtain.

+223:WAIT Wait the required time for the shutter trailing curtain to start moving.

≠224: PIO←O output capo) Outputs an L level signal to PIO, turns off transistor 123, and stops energizing magnet 122.

4225: Return As described above, return to the main screen in Figure 7 and perform preliminary light emission.
The exposure sequence of one memory flash is completed.

If the rear curtain synchronization mode is still selected by turning on the switch SO, the output of the comparator 134, which is 800 μAis pulled from the E terminal as explained in ≠226, will not be at H level. Capo) Pl7
Since is at H level, the process branches from ≠226 to -0227.

The flow performed from +227 will be described below.

4227: Pl 1←1 4228: WAIT +229: Pl 1←0 4230: TIMER4-TV +231: TIMBRP? This is exactly the same as 70-Loss 217 to -4221 above.

The front shutter curtain runs, the shutter time stored in the register TV is extended to real time by the timer circuit TIMEiR, the shutter time is counted, and +232.4233 is executed after a predetermined time elapses. Therefore, even if the front curtain travel is completed and the X contact is turned on, the D terminal remains at the H level, so the output of the inverter 40 shown in FIG. 1 is at the L level, and the AND gate 33 is closed. No flash emission occurs.

≠232:P16←10 11I-23'3:P22←O This command is exactly the same as ≠215.4=216. This command inverts the fiD terminal from H level to L level, and strobe light is emitted. It will be done.

Furthermore, when the TTL dimming mode is selected by the switch 55 of the strobe device shown in Fig. 1 and it is tilted toward the ground side, control is transferred to +16 by the judgment command shown at +10, and preliminary flashing is never performed. . When the switch 55 is on the ground side, or when the first stroke of the release button is pressed while preliminary light emission has not yet been performed, the switch SW1 is turned on, and the process branches to 4P17 based on a judgment command of ≠16. The flow after ≠17 will be described below.

≠17: P19←Q, P15←1. P16←1s18:
P18? 48. Similar to 49, it is determined whether the strobe device is fully charged, and if the strobe device is not fully charged, the process branches to ≠21, and if the strobe device is fully charged, the process branches to ≠19.

Now that it is complete, I will execute 4P19.

$19:CCCF←1 Set the strobe acceptance flag CCCF to 1.

+20: Subroutine, TTL strobe This is a subroutine for performing TTL light control, and will be explained in detail using FIG. 11.

+301:P9? switch SW by determining the state of F9 (input capo)
9 is detected to determine shutter priority or aperture priority. During shutter priority, SW9 is on, so +3
Go to 02.

4302:TV←ATP The shutter time is stored in register TV from ATP.

$303: TV: 250 + 304: TV←250 When the shutter second time stored in the register TV is greater than the full-open second time 1/250 second, the TV is set to 17250.
By setting the second, slit exposure is prohibited.

≠305: P4O10 1 is output to the output port P20, the switch 106 is closed, and the outputs of the light receiving elements 104 and 105 are combined to perform average photometry.

+306: Ev4-AD P The average photometric value, ie, the output of the operational amplifier 107, is AD converted by the AD converter 90 and read.

+ 307: 5V4-I 80P; + 308
: AvO4-AvOP: This command is +10 each.
1. This is the same instruction as shown in ≠102, and the data of ISO sensitivity and lens aperture value are stored in register sv.
;Stored in AVO.

4309: Ev4-BY+8V+AVO4P310
: AV4-Ev-TV + 311 : Ay : Ay□ + 312 : Ay 4- Ay 4- AV.

$313: Ay; F22 4P314: Ay<-F22 This command is the same as the commands shown in ≠109 to +-114, and includes the I80 sensitivity, the lens's maximum aperture value, the brightness of the subject, and the set shutter speed. The CPU 60 calculates the aperture value from , detects whether or not the aperture value is within the control range of the camera, and automatically shifts the aperture value to within the control range when it is outside the range.

≠321: DAP 4-Sy This command determines the output of the D/A converter. As shown in FIG. 4C, the mirror 408 is located at the shutter 4.
When the film 402 is exposed with the film 402 open, the amount of light reflected from the surface of the film 4020 and incident on the light receiving element 95 is quite small. If the ratio at this time is, for example, 1/32, the appropriate exposure amount is 2'V""X
O, ux・Sec, In order to output the strobe stop signal with the appropriate film exposure amount, the current of the light receiving element 95 should be 32
x 2"V-5=2""V times as much as possible. Therefore, the contents of register Sv are output to the DAP boat.

! #322: TvDP4-TV AvDP4-AV EBARP←O MBARP←0 Displays the calculated shutter time and aperture value on the LED display section 300. In addition, ``OOH is outputted to the LCD display unit 200 so that nothing is displayed.Also, when the strobe full TTL flash control mode is selected and aperture priority shooting is selected, ≠301 branches to ≠315. .

Below, 70- from $315 to ≠320 will be explained.

+ 315 2 AV4-ATP $316:Ty←1/250 By executing these commands, fiATP stores the aperture setting value in the register AV and reduces the shutter speed by 1/250.
Set the synchronization time to 250 seconds.

+317: sv←xsop +318: AvO4-AvOP With these instructions, the ISO sensitivity is stored in the register Sv from j5IsOP, and the lens open aperture value is stored in the register Avo from AvoP.

Naa 19: Ay: Av.

++320: Av+-Av.

These instructions are the same as ≠111.4112,
The aperture setting value is controlled to be smaller than the open aperture v value.

After the flow of subroutine TTL strobe is performed as described above, TTL light adjustment is performed by +23 and +25 subroutine exposure.

Valve 23: P2? This command detects the state of switch SW2 by determining the state of input port P2, and determines whether the second stroke of the release button is on, and if 8W2 is not on, then The flow is +7 → +16 → +17 → +18 → +19 → +20 →≠
The loop of 23 is repeatedly executed, and when SW2 is turned on, +25 subroutine exposure is executed.

Next, subroutine exposure is performed in the same manner as described above, but EF
When the LK mode is selected, the switch 97 is turned off by the command P22←0 at +216, and the light receiving element 92 is turned off.
The comparator 99 starts integrating the photocurrent generated at
Therefore, even if a light emission stop signal is output from the D terminal, pre-light emission is performed, and R8F/F36 shown in FIG. Since the output of 0R39 is always at L level through 0R39, the output of AND47 is always at L level, so such a signal cannot be accepted, and the light emission stop operation is hardly accepted. However, switch 55
Since the TTL dimming mode is selected, the output of 0R39 is at H level, and the current generated by the light incident on the light receiving element 92 flows through the diode 93, operational amplifier 94 and D
The output voltage of the A converter 91 is expanded by 28V by the transistor 95 applied to the emitter, and the output voltage is increased to 28V by the transistor 95 applied to the emitter of the capacitor 96.
The light emission stop signal that is charged and output to the comparator 99 is transmitted to the control circuit 12 via the AND 47.
The light emission of the Xe discharge tube 11 stops.

The following flow is performed as described above.

In the above explanation, as mentioned at the beginning, before the power is turned on from the power supply circuit of the camera (not shown), the power switch 42 of the strobe device shown in FIG. 1 is already turned on.
A case will be described in which the capacitor 4 has been completely charged, but the capacitor 4 is not yet fully charged before a stain source is turned on to the camera's power supply circuit.

The flow from +1 to +7 and from ≠16 to 4P18 is the same as described above.

418:P18? In the above case, when the charging of the main capacitor 4 of the strobe device shown in FIG. The output voltage of the operational amplifier 128 becomes high, the output of the comparator 135 goes to H level, and the input capacitor PI 8 signal goes to H level, so the instruction branches to +19, but charging of the main capacitor 4 (not completed) In case d, transistor 5
1 is turned off, no current flows from the output terminal, the output of the comparator 135 remains at the L level, and the signal at the input 4-to-P18 is at the L level, so the instruction branches to +21.

≠21:ccci;'←0 0 is stored in the flag CCCF, and the AE mode is stored.

+22: Subroutine AE metering Photometry for AE is performed by this subroutine.

The subroutine AE photometry will be explained below with reference to FIG.

+401:8W6? ≠402: P2O4-0 4403: P4O10 The above instructions are +151 in FIG. ≠152. This command is exactly the same as the command shown in ≠153, and is switched between average photometry and partial photometry according to the state of switch SW6 by changing the state of output capo P2O.

+ 404: P 21←1, BV4-ADP
This command is the same as the command shown at 4154 in FIG. 90 inputs. Further A/
The D conversion result is read into the register 13v.

Temple 405: SV←I SOP +4062 AVo4-AvOP Temple 407: EV4-Bv 10 Sv 10 AvO The command above is exactly the same as +101.4102° +109 shown in Figure 8, and is the maximum aperture value of an I80 sensitive lens. are stored in registers SV and AVO, respectively, and the EV value is determined by adding these data.

4408:P9? This command is the same as ≠103 shown in FIG.

The flow is branched depending on the state of the switch 8W9 for switching the priority shooting mode.

4409: Tv4-ATP + 410: Ay 4- Ey -'Ty+41'
l:Ay:Av.

44 1 2: Ay←Av.

+1-413-AV;F'22 +414: AV4-F'22 The above instructions are 104. shown in FIG. ≠110～≠1
This is the same command as 14. That is, A'I' at ≠409
P, read the shutter time into register TV. +41
At 0, the aperture is determined from the register Ev and the register TV and stored in the register AV, and at ≠411 to +414, when the determined aperture AV is larger than the minimum aperture F22 of the lens, AV is set to the minimum aperture F22, and the maximum aperture is smaller than Avo. Then set register Ay to open aperture AVO and go to #421.
In the case of aperture priority, the process branches from #408 to #415.

+ 415: AV4-ATP + 416: TV4-EV-AV + 417: Tv: TVMAX≠418:
'rV-'I''vMAx4419: Tv: TV
MIN 4420: Tv4-TVMIN +415 reads the aperture setting value from ATP into register AV, calculates the shutter speed with +416, and stores it in register T.
Store in V.

At 1417.4418, the shutter time is Tv MAX
(For example, 1/4000 second)
When VMAX I TVMIN is smaller than (for example, 30 seconds), T is the shutter time.

MIN + 421: 'rvI)p4-'11'vTvDP
+-Av EB, A, RP←O MBARP←0 This command is the same as the command shown in +322, and the LED
Ty and Ay are applied to the latch circuits 301 and 302 of the display section 300.
Displays the output set value and calculated value in the viewfinder. LC by sending 0 to EBA, RP, MBARP
D is not displayed. Also, while the first stroke of the release button is held down and the switch SWI is ON, the CPU
60 is ≠7-≠16-+18-421-fathom 22-≠23
The loop continues to be executed repeatedly. If the release button is pressed halfway through the second stroke, switch SW2
is turned on, and the ≠25 subroutine exposure shown in FIG. 10 is executed.

In the subroutine exposure shown in FIG. 10, 4201~-$
The first release of the camera and the aperture control in step 213 are the same as in the strobe mode.

≠214: CCCF Flag The state of CCCF is determined, but since 0 has been assigned in #21, the process goes to ≠217. Shutter control is completed at ≠217 to ≠224. At this time, output port P16
Since the output of the terminal D remains at the H level, the strobe does not emit light even if the X contact 124 is turned on. Therefore, during the release sequence, the strobe,
Even after charging is completed, strobe light will no longer be emitted when the shutter speed is controlled by AE.

<Effects of the Invention> As explained above, according to the present invention, when at least the shutter speed is automatically changed to be suitable for flash photography, the system automatically adjusts the shutter speed and aperture value from the changed shutter speed and aperture value. The deviation between the calculated control exposure value and the appropriate exposure value for properly photographing the screen obtained by metering the shooting screen is displayed, so for example when the main subject is backlit against a blue sky background. During daytime synchronized shooting where you are trying to properly photograph both the background and the main subject, the control exposure value is smaller than the appropriate exposure value, and even if the background is overshot, the aperture of the photographic lens or shutter speed can be changed. By doing so, it is possible to properly photograph both the background and the main subject.

[Brief explanation of drawings]

Fig. 1 is a circuit block of a strobe device according to an embodiment of the present invention, Fig. 2 is a time chart of the circuit block shown in Fig. 1, and Fig. 3a is a diagram showing a case where slow synchronization photography is performed in front curtain synchronization mode. Figure 3b shows an example of a photograph taken when slow synchro photography is performed in rear-curtain sync mode; Figure 4a is a camera control used with the strobe device shown in Figure 1. Circuit block diagram, 4th
Figures b and 4C are cross-sectional views of a camera used with the strobe device shown in Figure 1, showing the mirror in a lowered state and the mirror in a raised state, respectively. Fig. 4d is a diagram showing the display in the viewfinder of the camera shown in Figs. 4a to 4C, Fig. 5a is a circuit diagram of the LCD display section shown in Fig. 4a, and Fig. 5b is a diagram of the display element of the LCD display section. Figure 6a is a circuit diagram of the LED display part shown in Figure 4a, Figure 6b is a diagram showing the arrangement of display elements in the LED display part, Figures 7 to 12 are the circuit diagrams shown in Figure 4a. Microcomputer flowchart. FIG. 13 is a diagram showing a table used in step-4P128 shown in FIG. a... Optical integration circuit, 60... CPU, b... Dimmer circuit, ≠120-≠129... Dimmer circuit during pre-flash. Flowchart to remember.ヲρρ ÷ 7? ETtJRN

Claims (1)

[Claims] (1) In a flash photography device in which at least the shutter time is automatically changed to be suitable for flash photography at the time of flash photography, a photometry means for metering the photographic screen and outputting an appropriate exposure value for properly photographing the screen. and a means for outputting a control exposure value calculated from the shutter speed and aperture value during flash photography that have been changed to be suitable for flash photography, and displaying a deviation between the appropriate exposure value and the control exposure value. 1. A display device for a flash photography device, comprising: display means.