JP2001117147A - Stroboscopic device and its voltage data deciding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify the adjustment of a stroboscopic device. SOLUTION: In this stroboscopic device, an electronic volume linearly converting voltage data to voltage is used in order to generate reference voltage for controlling exposure by strobe light. Reference voltage data for Normal necessary to obtain standard exposure in a Normal mode is decided by measurement. The reference voltage data for a Light mode and a Dark mode are decided by performing calculation using a difference between the standard exposure and exposure in each mode and the reference voltage data for Normal.

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flash device and a method for determining voltage data of the flash device.

[0001]

2. Description of the Related Art Many cameras are equipped with a flash unit of an automatic light control type. In this strobe device, strobe light reflected from a subject is received by a light receiving circuit including a light receiving element or the like, and light amount integration is performed. When a voltage corresponding to the integrated amount reaches a predetermined reference voltage, strobe discharge is performed. Prevents discharge of the main condenser in the tube and stops strobe light emission. Thus, the emission amount of the strobe light is adjusted so that an appropriate exposure amount can be obtained.

In an instant camera, since the instant film itself becomes a print photograph without performing a normal printing process, when adjusting the density gradation of the print photograph, the exposure amount is adjusted at the time of photographing. There is a need. For this reason, an exposure correction (fractional control) function is provided, which allows the user to correct the exposure amount with an appropriate correction width based on the standard exposure amount. If the exposure is corrected at the time of flash emission, the amount of flash light emission is increased or decreased by increasing or decreasing the reference voltage.

Since the reference voltage determines the amount of light emitted by the strobe light, that is, the amount of exposure by the strobe light, it is necessary to adjust the reference voltage to an appropriate value in consideration of variations in the sensitivity of the light receiving element. . In particular, in an instant camera, since the density gradation of a printed photograph is determined by the exposure amount at the time of photographing, high-precision control of strobe light emission is required, and it is necessary to adjust the reference voltage with high accuracy.

In a conventional instant camera, a required reference voltage is obtained by applying a constant voltage to a voltage dividing circuit in which a plurality of resistors are connected in series in order to obtain a reference voltage.
The reference voltage is adjusted by changing the resistance value of the variable resistor. In some compact cameras and the like, instead of using a variable resistor, voltage data output from a microcomputer or the like is electrically converted by an electronic volume to generate a required reference voltage.

[0005]

By the way, in the strobe device which adjusts the reference voltage by the variable resistor as described above, the strobe light is actually emitted and the light is output from the light receiving circuit so that an appropriate voltage value can be obtained. The resistance value of the variable resistor was manually adjusted while comparing the applied voltage with a reference voltage. For this reason, the working effect is poor such as a long working time, and the accuracy of the adjustment is limited, and it is difficult to perform the adjustment with high accuracy.

Further, even when an electronic volume having an electric adjustment and conversion function is used, the electronic volume is given to the electronic volume according to a required reference voltage in consideration of variations in sensitivity of the light receiving elements of the light receiving circuit. Voltage data to be determined must be determined. Therefore, in this case as well, an adjustment operation for determining the voltage data to be applied to the electronic volume while comparing the voltage from the light receiving circuit obtained at this time with the reference voltage obtained from the electronic volume is performed. There is a need to do. This operation can be automatically performed by an adjusting device equipped with a computer or the like, but when a plurality of reference voltages are required, that is, for a strobe device having an exposure correction function, each selectable A similar adjustment operation must be repeatedly performed for each exposure amount, and there is a problem that the adjustment takes time.

If the strobe device is made to perform exposure correction with a fine correction width, or if exposure correction can be performed with an arbitrary correction width, a very large amount of voltage data must be determined at the time of adjustment. There is a problem that the time becomes longer.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is possible to shorten the adjustment time for determining the voltage data and to arbitrarily correct the exposure while shortening the adjustment time. It is an object of the present invention to provide an apparatus and a method for determining voltage data thereof.

According to a first aspect of the present invention, there is provided a method of determining voltage data for a strobe device, wherein an integrated voltage corresponding to a predetermined reference exposure amount by a strobe light is obtained by actual measurement. The reference voltage data necessary for obtaining an integrated voltage from the reference voltage generation means is determined, and a difference between the reference exposure amount and the exposure amount designated by the designation means, and a predetermined value using the reference voltage data. Is calculated to determine the voltage data corresponding to each exposure amount specified by the specifying means.

According to a second aspect of the present invention, there is provided a method for determining voltage data of a strobe device, wherein the strobe device is provided with storage means for storing voltage data. The voltage data is inputted to the voltage generating means, and each voltage data determined by performing the above calculation at the time of adjustment is stored in the storage means. According to a third aspect of the present invention, there is provided a method for determining voltage data of a strobe device, wherein the strobe device includes a storage unit for storing reference voltage data determined at the time of adjustment, and a calculation unit for performing an operation. The voltage data corresponding to the designated exposure amount is determined by the calculating means.

According to a fourth aspect of the present invention, at least a standard exposure amount can be specified by the specifying means, a reference exposure amount is set to the standard exposure amount, and reference voltage data corresponds to the standard exposure amount. This determines voltage data.

According to a fifth aspect of the present invention, an integrated voltage corresponding to a predetermined reference exposure amount by the strobe light is obtained by actual measurement, and reference voltage data necessary for obtaining the integrated voltage from the reference voltage generating means is determined. The storage means storing the reference voltage data, and a predetermined calculation using the difference between the reference exposure amount and the exposure amount specified by the specification means, and the reference voltage data, whereby the specification means Calculating means for determining reference voltage data corresponding to a designated exposure amount, wherein the voltage data is determined by the calculating means at the time of strobe light emission.

According to a sixth aspect of the present invention, at least the standard exposure amount can be specified by the specifying means, a reference exposure amount is set as the standard exposure amount, and voltage data corresponding to the standard exposure amount is determined as reference voltage data. The voltage data is stored in the storage means.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 2 shows an instant camera equipped with an automatic light control type flash device embodying the present invention. At the front of the camera body 2 of the instant camera 1, a collapsible lens barrel 3 and a light emitting window 4 for autofocus are provided.
And a light receiving window 5 are provided. The lens barrel 3 holds a photographing lens 6, and a photometric window 7 for measuring the luminance of the subject and a strobe light receiving window 8 are provided on the front surface of the lens barrel 3. A release button 10 is provided on the grip unit 9, and a flash light emitting unit 11 of a flash device and a finder 12 are provided above the release button 10. On the upper surface of the camera body 2, a main switch button 13, a setting button 14, an LCD 15, and a discharge port 16 are provided.

The inside of the grip portion 9 is a battery chamber, in which four batteries as a power supply, for example, four AA batteries are loaded. In the battery compartment, there is an instant camera 1
There are provided various terminals for connecting the internal circuit and an external adjustment device.

Each time the main switch button 13 is pressed, the power of the instant camera 1 is switched on and off alternately. When the power is turned on, the lens barrel 3 is extended to a photographing position protruding forward from the retracted position shown in the drawing, and becomes ready for photographing. When the power is turned off, the lens barrel 3 is returned to the retracted position, and no photographing is performed even if the release button 10 is pressed.

In the back of the light projecting window 4 and the light receiving window 5, a light transmitter and a light receiver for distance measurement are incorporated, and in the rear of the light measuring window 7, a light receiving element for photometry is arranged. Further, a phototransistor 18 (see FIG. 3) as a light receiving element for automatic light control is arranged behind the strobe light receiving window 8.

When the release button 10 is half-pressed, distance measuring light is projected from the distance measuring light projector toward the object, and the reflected light is received by the light receiver to measure the object distance. The luminance of the subject is measured by the light receiving element through. Subsequently, when the release button 10 is fully pressed, the focusing of the photographing lens 6 is performed in accordance with the measured subject distance, and then the opening and closing control of the shutter blade is performed based on the measured subject brightness. Exposure to the instant film 17 is performed.

The exposed instant film 17 is discharged from a discharge port 16. At the time of discharging, the developer pod 17a of the instant film 17
6 ruptured by a pair of developing rollers provided in the back,
The developing solution contained in the developer pod 17a is developed inside. As a result, the instant film 17
Is completed, and after a lapse of a predetermined time, a printed photograph is obtained.

By operating the setting button 14, a strobe light emission mode and an exposure correction mode can be selected. L
The CD 15 has a strobe light emission mode, an exposure correction mode,
Information necessary for shooting, such as the number of remaining instant films and the remaining battery capacity, is displayed.

As the strobe light emission mode, one of an automatic light emission mode and a light emission inhibition mode can be selected. In the automatic light emission mode, when the luminance of the subject is equal to or lower than a predetermined level, strobe light emission is automatically performed in synchronization with opening and closing of the shutter blades, and strobe light is emitted from the strobe light emitting unit 11 toward the subject. In the light emission prohibition mode, no strobe light is emitted regardless of the subject brightness.

The strobe light reflected by the subject at the time of the strobe light emission is received by the phototransistor 18, and the strobe emission is stopped when the amount of light received by the phototransistor 18 reaches a predetermined level. During flash emission, the shutter blades are opened and closed at a predetermined shutter speed and aperture value for flash emission.

The exposure correction mode includes a "normal mode" in which a printed photograph has a standard density gradation, a "light mode" in which a light density gradation is obtained, and a "dark mode" in which a printed density gradation is dark. Can be specified.

In the "Normal mode", the shutter speed and the aperture value are controlled so that the standard exposure amount is obtained and the strobe light is not emitted when the strobe light is not emitted. The amount of light emission is controlled. In “Light mode” and “Dark mode”, for example, +2/3 with respect to “Normal mode”
Exposure correction is performed with a correction width of EV, − ／ EV. This exposure correction is performed by controlling the shutter speed and the aperture value when no flash light is emitted, as in the “Normal mode”. However, when the flash light is emitted, the light emission amount of the flash light is kept under a constant shutter speed and aperture value. It is performed by the control of. That is, at the time of strobe light emission, the amount of exposure by the strobe light is increased or decreased according to the exposure correction mode.

FIG. 3 shows a main structure of the instant camera 1 and an adjusting device 40 for adjusting the strobe device. The microcomputer 20 of the instant camera 1
Is composed of a CPU, an interface for inputting and outputting signals and data to and from each unit, and the like. The microcomputer 20 controls the operation of the entire instant camera according to a sequence program stored in the ROM 21.

The RAM 22 is used as a work memory in which data necessary for performing a sequence is temporarily written. In the EEPROM 23, Normal reference voltage data, Light reference voltage data, and Dark reference voltage data determined by the adjustment device 40 as described later are written at the time of adjustment.

The strobe device includes a step-up circuit 24, a main capacitor 25, a charging voltage detecting circuit 26, and a strobe discharge tube 2.
7, a trigger circuit 28, a dimming circuit, and the like, and are controlled by the microcomputer 20.

The booster circuit 24 includes the microcomputer 2
It operates while the charging signal from 0 is being input, and converts the low voltage of the battery into a high voltage alternating current and outputs it. The alternating current output from the booster circuit 24 is rectified by the rectifying diode 24 a and supplied to the main capacitor 25, which charges the main capacitor 25.

The microcomputer 20 detects the charging voltage of the main capacitor 25 based on the detection voltage output from the charging voltage detection circuit 26 connected to the main capacitor 25, and when the voltage reaches a predetermined specified charging voltage. The transmission of the charging signal is stopped and the main capacitor 25 is stopped.
Stop charging. Main capacitor 25 by natural discharge
When the charging voltage becomes lower than the specified charging voltage, the microcomputer 20 restarts sending the charging signal. As a result, the charging voltage of the main capacitor 25 is kept substantially at the specified charging voltage.

The strobe discharge tube 27 includes a strobe light emitting unit 1
1. The strobe discharge tube 27 is connected in parallel with the main condenser 25, and an IC is provided between the main condenser 25 and the strobe discharge tube 27.
A GBT (insulated gate bipolar transistor) 29 is connected. The IGBT 29 is turned on (conducting state) prior to flash emission, as described later.

The trigger circuit 28 receives from the microcomputer 20 a synchro signal synchronized with the opening and closing of the shutter blades. When the sync signal is input, the trigger circuit 28 applies a trigger voltage to the strobe discharge tube 27.
As a result, the electric charge of the main capacitor 25 is discharged through the strobe discharge tube 27 via the IGBT 29 which is turned on, and the strobe light emission is started. The strobe light emitted from the strobe discharge tube 27 is emitted from the strobe light emitting unit 11 toward the subject. When the strobe light is not emitted, the microcomputer 20
The sync signal is not sent to the trigger circuit 28.

The light control circuit includes a light receiving circuit 30, an electronic volume 32, a voltage comparator 33, and an IGBT 29. The light receiving circuit 30 includes the phototransistor 18
, A capacitor 30a, and resistors 30b and 30c. A fixed voltage is input to the collector terminal of the phototransistor 18. A resistor 30 connected in series is connected between the emitter terminal of the phototransistor 18 and the ground.
b and the capacitor 30a are connected, and these resistors 30b
A resistor 31c is connected in parallel with the capacitor 30a. A voltage generated between the ground and the connection point between the emitter terminal of the phototransistor 18 and the resistor 30b and the ground is output from the light receiving circuit 30 as an integrated voltage _Vph .

The phototransistor 18 receives the strobe light reflected by the subject, and supplies a photocurrent according to the amount of the received strobe light. This photocurrent charges the capacitor 30a via the resistor 30b. The integral voltage _Vph increases in proportion to the increase in the charging voltage of the capacitor 30a due to this charging. In this way, the light receiving circuit 30 receives the reflected light from the moment when the strobe discharge tube 27 emits light, performs light amount integration, and outputs an integrated voltage _Vph corresponding to the integrated amount.

The capacitor 30a includes resistors 30b and 30c
To discharge through. When the strobe light emission is stopped by this discharge, the integration voltage _{Vph is set} to almost 0 V, and the integration circuit 3
In addition to initializing 0, when the strobe light emission is not performed, the photo transistor 18 prevents natural light or room light from being received and prevents the integrated voltage _Vph from rising. At the time of strobe light emission, the intensity of the received strobe light is high, so that charging of the capacitor 30a proceeds, and the integrated voltage _Vph increases. Note that instead of the phototransistor 18,
A light receiving element such as a photodiode may be used.

The integrated voltage V _ph is input to the inverting input terminal of the voltage comparator 33. This voltage comparator 33
, A reference voltage V _out output from the electronic volume 32 is input to the non-inverting input terminal. Voltage comparator 33 outputs a comparison signal according to the magnitude relationship between the integral voltage V _ph and the reference voltage V _out to the IGBT 29.

The voltage comparator 33 sets the comparison signal to "H level" when the integrated voltage _Vph is smaller than the reference voltage _Vout , and when the integrated voltage _Vph reaches the reference voltage _Vout ,
Strictly, when the integrated voltage _Vph slightly exceeds the reference voltage _Vout , the comparison signal is set to "L level". The comparison signal “H
The “level” is equal to or higher than the gate voltage required to turn on the IGBT 29.
It has become. As a result, the integrated voltage _Vph is
IGBT 29 is turned ON is smaller than _out, when the integrated voltage V _ph reaches the reference voltage V _out IGBT 29 is turned OFF.

The IGBT 29 is turned on prior to strobe light emission as described above. That is, when the integrated voltage V _ph from the light receiving circuit 30 is substantially 0 V, the IGBT 29 is turned on by applying the reference voltage V _out (> 0 V) to the voltage comparator 33. Then, during the strobe light emission, the phototransistor 18 receives the strobe light reflected by the object, and at the moment when the amount of received light reaches a predetermined level and the integrated voltage _Vph reaches the reference voltage _Vout , the IGBT
29 is turned off, the connection between the strobe discharge tube 27 and the main condenser 25 is cut off, and the strobe light emission is stopped.

As is well known, the electronic volume 32 has a D /
It is composed of an A-converter and the like, and is used as reference voltage generating means for linearly converting input voltage data into a voltage and outputting the voltage. That is, the electronic volume 32
Outputs an output voltage V _out proportional to the magnitude of the input voltage data. The microcomputer 20 converts the reference voltage data corresponding to the designated exposure correction mode into E
The data is read from the ERPOM 23 and given to the electronic volume 32. Thereby, a reference voltage V _out corresponding to each exposure correction mode is obtained from the electronic volume 32, and the reference voltage V _out is given to the voltage comparator 33.

The instant camera 1 and its strobe device configured as described above operate as follows. When the release button 10 is half-pressed, the measurement of the subject distance by the light emitting device and the light receiving device for distance measurement and the measurement of the subject brightness by the light receiving element for photometry are performed. When the subject brightness is equal to or lower than the predetermined level in the automatic light emission mode, the exposure correction mode designated by the setting button 14 is checked, and the reference voltage data corresponding to the designated exposure correction mode is read from the EEPROM 23 to the microcomputer 20.
And sent to the electronic volume 32.

For example, when the "Normal mode" is designated, the reference voltage data for Normal
The data is read from the EPROM 23 and sent to the electronic volume 32. The electronic volume 32 is Normal
When the reference voltage data for use is input, a reference voltage _{Vout corresponding} to the input is output. The reference voltage V _out from the electronic volume 32 is provided to a non-inverting input terminal of the voltage comparator 33. In this case, the reference voltage V
_out is a reference voltage value V _N for the “Normal mode”, and this reference voltage value V _N differs for each instant camera due to variations in the light receiving circuit 30, particularly, variations in the sensitivity of the phototransistor 18.

On the other hand, in the light receiving circuit 30, the phototransistor 18 receives natural light or room light and flows a photocurrent. The magnitude of the photocurrent at this time is very small. For this reason, the electric charge accumulated in the capacitor 30a due to natural light or the like is reduced by almost no increase in the charging voltage of the capacitor 30a.
It is discharged through Ob and 30c. Therefore, the integration circuit 30 is in a state where the integrated voltage _Vph of almost 0 V is applied to the inverting input terminal of the voltage comparator 33.
As a result, when the reference voltage _Vout is output from the electronic volume 32, the integrated voltage _{Vph is} higher than the reference voltage _Vout.
Is low, the voltage comparator 33 outputs “H level”
Is output, and the IGBT 29 is turned ON.

When the release button 10 is further depressed and fully pressed, after the focusing of the photographing lens 6 is performed in accordance with the previously obtained subject distance, the shutter device is operated, and the shutter speed for the strobe light is used. The shutter blade is opened and closed by the and the aperture value. When the shutter blade reaches the maximum opening diameter when opening and closing the shutter blade, a sync signal is input from the microcomputer 20 to the trigger circuit 28. Then, a trigger voltage is applied to the strobe discharge tube 27 by the trigger circuit 28.

Thus, the main capacitor 25 charged to the specified charging voltage by the booster circuit 24 after the power is turned on is discharged by the strobe discharge tube 27 via the IGBT 29 which is turned on. As a result, flash emission is started.

The strobe light emitted from the strobe discharge tube 27 is emitted from the strobe light emitting section 11 toward the subject, and a part thereof is reflected and enters the phototransistor 18 through the strobe light receiving window 8. The phototransistor 18 supplies a photocurrent according to the incident strobe light, and the photocurrent charges the capacitor 30a. As the amount of received light increases, the charging voltage of the capacitor 30a increases.

The integral voltage _Vph increases in proportion to the increase in the charging voltage of the capacitor 30a. When the integrated voltage _Vph reaches the reference voltage _Vout , the comparison signal from the voltage comparator 33 changes to "L level",
The BT 29 is turned off. When the IGBT 29 is turned off, the main capacitor 25 and the strobe discharge tube 2 are turned off.
The connection with 7 is cut off, and the flash emission stops.

As described above, when the "Normal mode" is designated, the amount of light emission of the strobe light is controlled so that the amount of exposure of the instant film 17 with the strobe light becomes the standard exposure amount. A print photograph having a proper density gradation can be obtained.

On the other hand, when the “Light mode” is designated, the reference voltage data for Light is EEPR
It is read from the OM 23 and sent to the electronic volume 32. As a result, the electronic volume 32 stores “Li
The reference voltage V _out of the reference voltage value _VL for the “ght mode” is output. Thereafter, in the same manner as in the “Normal mode”, strobe light emission is performed. When the integrated voltage _Vph reaches the reference voltage _Vout of the reference voltage value _VL , the strobe light emission is stopped.

Similarly, when the “Dark mode” is designated, the reference voltage data for Dark is EEPRO
Read from M23, by which is sent to the electronic volume 32, a reference voltage V _out of _the reference voltage value V _D for "Dark mode" is sent from the electronic volume 32 to a voltage comparator 33, to the reference voltage V _out When the integrated voltage _Vph reaches, strobe light emission is stopped.

Thus, when the "Light mode" is designated, a print photograph having a density gradation lighter than a standard density gradation is obtained, and "Dar mode" is selected.
When the "k mode" is designated, the exposure amount by the strobe light is increased or decreased with respect to the standard exposure amount so as to obtain a print photograph having a dark density gradation.

At the time of "Light mode" and "Dark mode"
The reference voltage output from the electronic volume 32 at the time of
Pressure V_out, That is, the reference voltage value V_L, Reference voltage
Value V _DIs the reference voltage value V_NLike, PhotoTransis
Instant camera due to variations in sensitivity of
Although different for each device, the same strobe device
Pressure value V_NAnd the following relationship. V_L= V_N・ 2^ZL... V_D= V_N・ 2^ZD ...

The values “ZL” and “ZD” in the above equation are “N
This is a difference between the exposure amount (EV) of the “Light mode” and the “Dark mode” with respect to the “normal mode”. In this example, the value “ZL” is “+２”, and “ZD” is “−2”.
/ 3 ".

The respective reference voltage data corresponding to the reference voltage values V _N , V _L , V _D are supplied to the adjusting device 4 at the time of adjustment by the manufacturer.
0 and is written to the EEPROM 23.

The adjusting device 40 includes the phototransistor 4
1, integration circuit 42, reference voltage generation circuit 43, voltage comparator 44, A / D converter 45, latch circuit 46, first
It comprises a selector 47, a second selector 48, an adjustment microcomputer 50 and the like.

The microcomputer 50 for adjustment uses the RO
The operation of the entire adjustment device 40 is controlled according to the sequence program stored in M51. The adjustment microcomputer 50 gives instructions to the connected microcomputer 20 of the instant camera 1 to control each part of the instant camera 1. The RAM 52 is used as a work memory in which data necessary for performing the sequence is temporarily written.

At the time of the adjustment, the test microcomputer 50 emits a test light emission while measuring the integrated voltage V _ph by the adjustment microcomputer 50, and the normal reference voltage V
A test light emission sequence for determining _N , and measuring the output voltage _Vout of the electronic volume 32 while controlling the electronic volume 3
2, the normal reference voltage data determination sequence for determining the normal reference voltage data by changing the voltage data given to the “No. 2”, and “Light mode” and “Dar”.
An operation sequence for determining each reference voltage data for “k mode” by operation and a write sequence for writing the obtained three types of reference voltage data to the EEPROM 23 are sequentially executed.

In the test light emission sequence, the strobe device of the instant camera 1 is operated to make the strobe emit full light, and the strobe light is applied to a test reflector having a predetermined reflectance. Then, the strobe light reflected by the phototransistor 18 on the instant camera side and the phototransistor 41 on the adjustment device side is received.

The phototransistor 41 receives the strobe light reflected by the test reflector, and supplies a photocurrent according to the amount of received light. The integration circuit 42 integrates the amount of light based on the photocurrent from the phototransistor 41 and outputs an integrated voltage _Vtest corresponding to the amount of integration.

The reference voltage generation circuit 43 outputs a constant test reference voltage _Vref . This test reference voltage V
_ref is precisely adjusted so that the amount of strobe light corresponding to the Normal mode becomes the same as the integrated voltage V _test output from the integration circuit 42 when the test reflector is irradiated.

The voltage comparator 44 has an inverting input terminal to which the integrated voltage V _test is inputted, and a non-inverting input terminal to which the test reference voltage _Vref is inputted. This voltage comparator 44
, Upon test firing sequence, the integrated voltage V _test reaches the test reference voltage V _ref, to vary the output signal strictly slightly above the "H" level to the "L" level. The change of the output signal from “H level” to “L level” is given to the latch circuit 46 as a latch signal.

The first selector 47 has an electronic
The output of the volume 32 and the output of the light receiving circuit 30 are connected
The A / D converter 45 is connected to the output side. This
The first selector 47 receives the signal during the test light emission sequence.
Integrated voltage V from optical circuit 30 _phIs the standard for Normal
At the time of the voltage data determination sequence, the electronic volume 32
Reference voltage V from_outTo the A / D converter 45
Can be switched.

The A / D converter 45 converts the input voltage into a digital signal, converts it into measured voltage data, and outputs it. A
The / D converter 45 converts the measured voltage data into a second selector 48
Send to The second selector 48 supplies the measured voltage data to the latch circuit 46 during the test light emission sequence,
In the reference voltage data determination sequence for al, the measurement voltage data is switched to be sent to the microcomputer 50 for adjustment.

The latch circuit 46 includes a voltage comparator 44
When the latch signal is input, the measured voltage data input at that time is latched and sent to the adjustment microcomputer 50 as comparison voltage data. Therefore, when the test reflector is irradiated with the strobe light amount corresponding to the Normal mode, the measured voltage data obtained by A / D converting the integrated voltage _Vph output from the light receiving circuit 30 of the instant camera is latched by the latch circuit 46. Is sent to the adjustment microcomputer 50 as comparison voltage data.

The adjustment microcomputer 50 has a No.
In the rmal reference voltage data determination sequence, the microcomputer 20 is controlled by controlling the microcomputer 20 while comparing the comparison voltage data from the latch circuit 46 with the measurement voltage data obtained by A / D conversion of the reference voltage V _out of the electronic volume 32. The voltage data input to the volume 32 is changed. In this comparison, the voltage data obtained when the comparison voltage data and the measured voltage data match each other is referred to as Norma.
The reference voltage data for 1 is used.

In the operation sequence, Normal
Norma obtained in the reference voltage data determination sequence
The reference voltage data for Light mode and Dark mode are determined by applying the reference voltage data for 1 to the following equation. D _L = D _N · 2 ^ZL ... D _D = D _N · 2 ^ZD ...

D _N in the above equations is Norm determined by the Normal reference voltage data determination sequence.
al is the value of the reference voltage data, and D _L and D _D are the values of the light reference voltage data and the dark reference voltage data, respectively. The value “ZL” and the value “ZD” are “No”
This is a difference between the exposure amount (EV) of the “Light mode” and the “Dark mode” with respect to the “rmal mode”.

The reference voltage value V _L and the reference voltage value V _D have the relationship shown in the above equation with the reference voltage value V _N, and the relationship between the voltage data input to the electronic volume 32 and the output voltage Due to the linearity between them,
Each reference voltage data for Light and Dark can be determined by the equation.

In the write sequence, the microcomputer 50 sends each reference voltage data obtained by the Normal reference voltage data determination sequence and the operation sequence to the microcomputer 20, and writes the reference voltage data to the EERPOM 23 through the microcomputer 20.

It should be noted that the adjusting device 40 uses the Norma
1 is determined by actual measurement, and this Norm
By determining each reference voltage data for the Light mode and the Dark mode based on the reference voltage data for al by calculation, the calculation for obtaining the reference voltage data for Normal is omitted, and the adjustment work is made more efficient. . Further, the configuration of the adjustment device 40 shown in FIG. 3 is an example, and another configuration can be adopted as long as the above-described equivalent function can be realized.

Next, the operation of the above configuration will be described with reference to FIG. When manufacturing the instant camera 1,
Instant camera 1 completed with various components incorporated
Is sent to the adjustment process. In the adjusting step, the adjusting device 40 is connected to a terminal provided in the battery chamber. This allows
The microcomputer 20 on the instant camera side and the microcomputer 50 for adjustment on the adjustment device side are connected. The light receiving circuit 30 on the instant camera side and the electronic volume 32 are connected to the first selector 47 on the adjusting device side.

Further, the strobe light emitting section 11 and the strobe light receiving window 8 of the instant camera 1 are set in a posture facing the test reflector. At this time, the interval and the angle between the strobe light emitting unit 11 and the strobe light receiving window 8 of the instant camera and the test reflector, and the interval and the angle of the test transistor of the phototransistor 41 on the adjustment device side are fixed in advance. It is assumed that

After the connection is completed, the microcomputer 50 for adjustment supplies power to the instant camera 1 from a power supply circuit (not shown) to make each part of the instant camera 1 operable. Next, the adjustment microcomputer 50 sequentially executes the sequence.

In the test light emission sequence, first, each part of the adjustment device 40 is initialized. Thereby, the integration circuit 42
Are set to the state where the light intensity integration is “0”, and the reference voltage generation circuit 43 outputs the test reference voltage _Vref . Further, the first selector 47 is provided on the light receiving circuit 30 side with the second selector 47.
The selector 48 is switched to the latch circuit 46 side. Further, the A / D converter 45 is operated.

After the adjustment device 40 is initialized as described above, the adjustment microcomputer 50 operates the booster circuit 24 via the microcomputer 20 to charge the main capacitor 25 to the specified charging voltage. . After that, the microcomputer 20 is controlled to send a synchro signal to the trigger circuit 28 to make the strobe emit full light. For full light emission, for example, appropriate voltage data may be input to the electronic volume 32 and a sufficiently high reference voltage V _out may be supplied from the electronic volume 32 to the voltage comparator 33.

As described above, the strobe light is emitted from the strobe light emitting section 11 toward the test reflector. Then, a part of the strobe light reflected by the test reflector is received by the phototransistor 18, and the integrated voltage _Vph output from the light receiving circuit 30 increases accordingly. Then, the integrated voltage V _ph is input to the A / D converter 45 via the first selector 47, so that the second selector 48 becomes measured voltage data corresponding to the voltage value.
Is sent to the latch circuit 46 via the. The digital conversion by the A / D converter 45 is repeatedly performed in a short cycle.

On the other hand, on the adjustment device side, part of the strobe light reflected by the test reflector is received by the phototransistor 41 of the adjustment device 40, and a photocurrent corresponding to the amount of light received from the phototransistor 41 is integrated by the integration circuit 42. Flows to The integration circuit 42 integrates the amount of light based on the photocurrent from the phototransistor 41 and integrates the integrated voltage V according to the amount of integration.
Since outputs the _test, according to the irradiation amount of flash light to the test reflector increases, the integral voltage V _test is increased.

When the integrated voltage V _test reaches the test reference voltage V _ref , the output signal from the voltage comparator 44 changes from “H level” to “L level”, which is given to the latch circuit 46 as a latch signal. At this time, the measured voltage data being input is latched by the latch circuit 46.

As a result, Norma was added to the test reflector.
When the strobe light amount corresponding to the l mode is
In other words, the amount of light emitted from the strobe is at a level that provides the standard
At that point, the light receiving circuit 30 on the instant camera side
Integrated voltage V output from _phMeasured voltage data equivalent to
Data is latched by the latch circuit 46, and this is
The data is sent to the adjustment microcomputer 50 as data.

When the test light emission sequence is completed as described above, the adjustment microcomputer 50 continuously executes the Normal reference voltage data determination sequence. In the Normal reference voltage data determination sequence, first, the adjustment microcomputer 50
The selector 47 is switched to the electronic volume 32 side, and the second selector 48 is switched to the adjustment microcomputer 50 side.

Next, the adjustment microcomputer 50 is
Appropriate voltage data is input to the electronic volume 32 via the microcomputer 20. The electronic volume 32
The state is such that the reference voltage V _out having a voltage value corresponding to the voltage data is output.

The reference voltage V _out from the electronic volume 32
Is input to the A / D converter 45 via the first selector 47, is converted into measured voltage data corresponding to the voltage value, and is input to the adjustment microcomputer 50.

The adjusting microcomputer 50 is provided with A /
The measured voltage data from the D converter 45 and the latch circuit 46
Is compared with the comparison voltage data. In this comparison, when the measured voltage data is smaller than the comparison voltage data, the adjustment microcomputer 50 increases the value of the voltage data given to the electronic volume 32 by “1”, and the measurement voltage data is larger than the comparison voltage data. Is larger, the value of the voltage data is reduced by “1”. Then, the measured voltage data and the comparison voltage data are compared again.

As described above, while comparing the measured voltage data and the comparison voltage data, the voltage data is increased or decreased until they match. When the measured voltage data and the comparison voltage data match, the voltage data at this point is set to N
The data is temporarily stored in the RAM 52 as normal reference voltage data.

After storing the normal reference voltage data, the operation proceeds to the operation sequence, and the adjusting microcomputer 50 applies the value of the normal reference voltage data obtained as described above to the above-described equations and equations. L
The reference voltage data for light and the reference voltage data for Dark are obtained, and are temporarily stored in the RAM 52.

Next, the adjustment microcomputer 50
Executes a write sequence, sequentially reads out three reference voltage data from the RAM 52, sends them to the microcomputer 20, and reads these EEPROMs.
Instructs writing to M23. Thereby, for Normal, for Light, and for Da determined by the adjustment device 40.
Each reference voltage data for rk is written into the EEPROM 23. When the writing of each reference voltage data to the EEPROM 23 is completed, the operation of the adjustment process for the strobe device is completed.

As described above, the normal reference voltage data is determined by actual measurement, and the other reference voltage data is determined by calculation, so that the adjustment process is simplified and completed in a short time.

In the above embodiment, calculations for determining each reference voltage data for Light mode and Dark mode are performed on the adjustment device side. However, these calculations may be performed on the microcomputer of the instant camera. When the calculation is performed on the instant camera side, each reference voltage data obtained by this calculation may be written into the EEPROM, and when the strobe light is emitted, the reference voltage data may be read from the EEPROM and input to the electronic volume. EEPR only voltage data
The reference voltage data for the Light mode and the Dark mode may be stored in the OM, and the calculation may be performed for each strobe light emission.

FIG. 4 shows an example of a strobe device in which exposure correction is performed with an arbitrary correction amount (width) with respect to a standard exposure amount by using the same voltage data determination method as described above. Except for the following, the configuration is the same as that of the above-described embodiment.

In this example, the normal reference voltage data is determined by the adjusting device 40 in the same procedure as in the above embodiment, and only this normal reference voltage data is written into the EEPROM 23 of the strobe device. By operating the setting button 14 in the instant camera having the built-in strobe device, the correction amount can be specified almost steplessly with reference to the standard exposure amount. That is, by operating the setting button 14, an exposure amount corrected by an arbitrary correction amount with respect to the standard exposure amount can be designated.

At the time of flash emission, as shown in FIG. 4, the microcomputer 20 corrects the standard exposure amount designated by the setting button 14, that is, the difference between the designated exposure amount and the standard exposure amount. "Z" and Normal
The value of the reference voltage data “D _{N ”} is calculated using the arithmetic expression “D = D _N
* 2 ^Z "to obtain reference voltage data corresponding to the specified exposure amount,
Enter 2 Thereby, the light emission amount of the strobe light is adjusted so that the exposure amount specified by the setting button 14 is obtained.

According to the above strobe device, it is not necessary to determine the reference voltage data corresponding to the exposure amount corrected by an arbitrary correction amount with respect to the standard exposure amount at the time of adjustment.
Even if the correction amount can be specified almost steplessly as described above,
The adjustment time can be completed in a short time.

In each of the above embodiments, the normal reference voltage data is determined by actual measurement, and the light mode and Dar mode are determined based on the normal reference voltage data.
The reference voltage data for k mode and the reference voltage data corresponding to the exposure amount corrected by an arbitrary correction amount with respect to the standard exposure amount are determined, but the reference voltage data for Normal is always determined by actual measurement. No need. That is,
An arbitrary exposure amount (reference exposure amount) is determined, an integrated voltage _Vph when the exposure amount by the strobe light reaches this reference exposure amount is determined as a reference voltage, and this reference voltage is obtained from the electronic volume. The required reference voltage data is determined, and based on the difference between the reference exposure amount and the specified exposure amount and the reference voltage data, reference voltage data corresponding to the specified exposure amount can be obtained by calculation. .

In each of the above embodiments, the strobe device that controls only the exposure amount of the strobe light at the time of the strobe light emission has been described. For example, it can be used for mixed exposure control known from Japanese Patent Publication No. 5-4650.

Also, an example has been described in which the present invention is applied to a strobe device mounted on an instant camera. However, the strobe device of the present invention is applicable to various cameras such as a camera using a 135-type photographic film and a digital still camera. The present invention can also be used for a built-in strobe device or a strobe device mounted on a camera.

[0093]

As described above, according to the present invention,
In order to obtain the reference voltage corresponding to the exposure amount specified by the reference voltage generating means by inputting the voltage data, an integrated voltage corresponding to a predetermined reference exposure amount by the strobe light is actually measured, and this integrated voltage is used as a reference. The reference voltage data necessary for obtaining from the voltage generating means is determined, and the reference voltage corresponding to the specified exposure amount is determined from the difference between the reference exposure amount and the exposure amount by the designated strobe light and the reference voltage data. Since the data is determined, the adjustment work of the strobe device is simplified and the work time can be shortened

Further, storage means for storing reference voltage data, reference voltage data corresponding to the specified exposure amount, and a difference between the reference exposure amount and the exposure amount by the designated strobe light and the reference voltage data. Is provided in the flash device, it is possible to specify an arbitrary exposure amount while simplifying the adjustment work.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a main configuration of a strobe device and an adjustment device embodying the present invention.

FIG. 2 is a perspective view showing an appearance of an instant camera equipped with a strobe device embodying the present invention.

FIG. 3 is a flowchart illustrating a procedure for determining each reference voltage data.

FIG. 4 is a flowchart illustrating an example of a strobe device capable of performing exposure correction with an arbitrary correction width with respect to a standard exposure amount.

[Explanation of symbols]

 Reference Signs List 18 phototransistor 20 microcomputer 23 EEPROM 27 strobe discharge tube 30 light receiving circuit 32 electronic volume 40 adjusting device 50 adjusting microcomputer

Claims (6)

[Claims] 1. A designating means for designating an exposure amount by strobe light, a light receiving circuit for receiving strobe light reflected from a subject, integrating a light amount, and outputting an integrated voltage corresponding to the integration amount, and an input circuit. Reference voltage generating means for outputting a reference voltage proportional to the voltage data to be output, and the reference voltage obtained by inputting the voltage data corresponding to the exposure specified by the specifying means to the reference voltage generating means. A method of determining voltage data of a strobe device, wherein the strobe light emission is stopped in response to the integration voltage reaching, thereby adjusting the amount of strobe light emission so as to attain the exposure amount designated by the designation means. An integrated voltage corresponding to a predetermined reference exposure amount is obtained by actual measurement, and reference voltage data necessary for obtaining the integrated voltage from the reference voltage generating means is determined. To,
By performing a predetermined calculation using a difference between the reference exposure amount and the exposure amount specified by the specifying unit and the reference voltage data, voltage data corresponding to each exposure amount specified by the specifying unit is obtained. And determining the voltage data of the strobe device. 2. The strobe device according to claim 1, further comprising: storage means for storing voltage data, wherein at the time of strobe light, voltage data corresponding to the designation of the designation means is read from the storage means and input to the reference voltage generation means. Has been
2. The method according to claim 1, wherein each voltage data determined by performing the calculation at the time of adjustment is stored in the storage unit. 3. The strobe device includes a storage unit that stores the reference voltage data determined at the time of adjustment, and a calculation unit that performs the calculation.
2. A method according to claim 1, wherein said calculating means determines voltage data corresponding to the exposure amount specified by said specifying means. 4. The method according to claim 1, wherein the specifying unit is capable of specifying at least a standard exposure amount, sets the reference exposure amount as the standard exposure amount, and determines voltage data corresponding to the standard exposure amount as reference voltage data. The method for determining voltage data of a strobe device according to claim 1. 5. A designating means for designating an exposure amount by strobe light, a light receiving circuit for receiving strobe light reflected from a subject, integrating light amount, and outputting an integrated voltage according to the integration amount, and an input circuit. Reference voltage generating means for outputting a reference voltage proportional to the reference voltage data to be supplied, and a reference voltage obtained by inputting voltage data corresponding to the exposure specified by the specifying means to the reference voltage generating means. A strobe device for adjusting a light emission amount of the strobe light so as to attain an exposure amount designated by the designation means by stopping the strobe light emission in response to the arrival of the integrated voltage; An integrated voltage corresponding to the amount is obtained by actual measurement, and reference voltage data necessary for obtaining the integrated voltage from the reference voltage generating means is determined. By performing a predetermined calculation using the stored memory means, a difference between the reference exposure amount and the exposure amount designated by the designation means, and the reference voltage data, the exposure amount designated by the designation means is obtained. And a calculating means for determining reference voltage data corresponding to (i), wherein the voltage data is determined by the calculating means at the time of strobe light emission. 6. The designating means is capable of designating at least a standard exposure amount, using the reference exposure amount as the standard exposure amount, and determining voltage data corresponding to the standard exposure amount as reference voltage data. 6. The flash device according to claim 5, wherein the storage means is stored in said storage means. [0001]