JPH03144427A - Flash light emitting device - Google Patents

Abstract

PURPOSE:To obtain the effect of fully reducing a red-eye phenomenon and also to obtain a flash light emitting device whose useless power consumption can be reduced by providing a means for detecting the light quantity emitted by a flash light and a control circuit for controlling the timing of stopping the flash light emission for contracting a pupil based on receiving the output of the detecting means. CONSTITUTION:The quantity of light emitted by each pre-emission is detected by an emitted light quantity detecting means 7, and the emitted light quantity is controlled by a circuit for controlling the timing of stopping the light emission which is incorporated in a CPU 1 so that the light emission by a stroboscope 2 may be stopped when the prescribed light quantity is obtained. And when it is judged that there is the possibility of the occurrence of the red-eye phenomenon by performing an arithmetic operation for deciding whether or not the condition that the red-eye phenomenon occurs lies based on the distance between the optical axis of an image pickup lens and a stroboscopic flash light emitting tube and the distance between a range-finding circuit 5 and an object, the warning for the red-eye phenomenon is given by a display means 102, and then, a mode is switched to a red-eye phenomenon prevention mode by a mode setting means 3. Thus, the effect of fully reducing the red-eye phenomenon can be obtained and also the flash light emitting device with the remarkable effect of reducing the power consumption can be obtained.

Description

[Detailed description of the invention] [Industrial application field]
This invention relates to a flashlight emitting device with a red-eye phenomenon prevention function that can prevent the so-called red-eye phenomenon in which the eyes of a subject appear red when flashlight photography is performed using a L robot.

[Prior Art] Regarding the above-mentioned flashlight emitting device with a red-eye phenomenon prevention function, a camera having a flashlight emitting device described in Japanese Patent Application No. 1-22115 previously filed by the present applicant has a red-eye phenomenon prevention function. Metering in response to the 1st-stage release ON operation.
The p1 distance is further selected, and a strobe light emission mode and a red-eye prevention mode are selected, and then, in response to the ON operation of the second stage release, photographing is performed according to the selected mode. In the red-eye prevention mode, after the second-stage release operation, and before the flash for exposure (hereinafter referred to as main flash), multiple flashes of a predetermined constant time width similar to sunlight filtering through the trees are performed to constrict the pupils. Light emission (hereinafter referred to as pre-light emission) was performed.

[Problems to be Solved by the Invention] However, as described above, in the red-eye prevention mode of the conventional light emitting device, the pre-emissions performed multiple times are all performed with the same emission time width. Therefore, variations in the amount of emitted light occur due to "variations" in the light emission characteristics of the flash tube, fluctuations in charging voltage, etc., and a sufficient red-eye reduction effect may not be obtained.

An object of the present invention is to control the amount of emitted light during the pre-flash operation of a flashlight emitting device by providing a light emitting amount detection means so that a fixed amount of pre-flash can always be obtained, thereby sufficiently reducing red-eye. The present invention relates to a flash light emitting device which is effective and consumes less power.

[Means and Effects for Solving the Problems] The flashlight emitting device of the present invention performs a plurality of flashlight operations for pupil constriction, which is brilliance, and a flashlight operation for exposure, which is main light emission. The flashlight emitting device is characterized by comprising a means for detecting the amount of flashlight emission, and a control circuit that receives the output of the detection means and controls a special device for stopping the light emission of the flashlight emission for pupil constriction. The amount of light is detected by the detection means, and the control circuit stops the light emission when a predetermined amount of light is reached.

[Implementation example] The present invention will be explained below with reference to illustrated embodiments.

First, the main structure of a camera equipped with a flash light emitting device showing a first embodiment of the present invention will be explained with reference to FIGS. 1 and 2.

FIG. 1.2 is a block system diagram of the main parts of the camera. In the figure, the CPU, which is built into the camera body and controls the operation sequence of each circuit in the camera, and which also has a built-in pre-flash stop standby control circuit, includes an API optical recirculation circuit 10, a strobe 2, a mode setting means 3, a shutter A control means 4, a distance measuring circuit 5, a lens drive means 6, a flash light emission amount detection means 7, and a first switch SW1 which is turned on by pressing the release button (not shown) in the first step and turned on by pressing the release button (not shown) in the second step. A second switch SW2 is connected to the second switch SW2.

In addition, when connecting the strobe 2 to the CPUI, as shown in FIG. 2, the output voltage of the main capacitor of the strobe 2 is connected to the resistors R, R2.

The voltage is divided by a voltage dividing circuit made up of a capacitor C1 and then sent to the A/D port 1 of the CPU 1. Furthermore, an E2FROM 103 is connected to this CPUI.

Now, by pressing the release button one step, the first switch SWI
When turned on, the CPU first operates the photometry circuit 101 and the distance measurement circuit 5, takes in the photometry information and 'A11j distance information obtained from each circuit, and updates the RA in the CPU.
Store in M. When the camera and strobe 2 are set by the mode setting means 3 to flash photography mode or normal flash mode (mode that does not perform flash flashing for pupil constriction), a preset value, for example, the optical axis of the photographic lens It is calculated from the distance to the strobe flash tube and the subject distance from the distance measuring circuit 5 whether or not the conditions are such that red eye will occur, and if it is determined that there is a possibility of red eye occurring, the display means 102
causes a red-eye warning to be issued. If the red eye warning does not appear, press the release button again and turn the second switch S.
W2 is turned on, whereby the lens drive means 6, shutter control means 4, and strobe light 2 are operated to perform a normal photographing operation. On the other hand, if a red eye warning display is issued, the mode setting means 3 switches to the red eye prevention mode. In this case, from the time when the second switch SW2 is turned on until the shutter control means 4 is activated, a flash light emission pulse for red eye prevention is sent out multiple times, and a flash light emission is performed.

The light emission amount of each of the above-mentioned flash lights is detected by the light emission amount detection means 7, and a light emission stop I timing control circuit built in the CPUI is used so that the light emission of the strobe 2 is stopped when a predetermined light amount is reached. be controlled.

The light receiving element PDI constituting the detection means 7 is fixed to the inner surface of the reflector 10 near the flash tube (Xe tube) of the strobe 2, as shown in FIG.

On the other hand, regarding charging of strobe 2, as shown in Figure 2, a voltage equivalent to the voltage of the main capacitor of strobe 2 is divided by resistors R1 and R2, and the CPU A/D
It is converted into a digital signal by manual input into the human support 11.

When the value of this digital signal reaches a preset value, the CPUI changes the logic level of its output port 01 to L-
By setting it to H, the operation of the DC/DC converter of the strobe 2 is stopped. Furthermore, if the CPU determines that the release button has been pressed twice during charging, charging will be stopped regardless of whether the battery is uncharged or not.

After that, if the red-eye prevention mode is set, the battery will be charged to compensate for the shortage, and will perform flash flashing, lens drive, one flash with the shutter open, one winding with the shutter closed, and charging. Also,
If the camera is not in red-eye prevention mode, the lens will be driven, the shirt lid will open, the main flash will be fired, the shirt lid will close, winding, and charging will be performed. By the way, the correction of the variation in the resistance values of the resistors Rt and R2 is stored in the E2PROM 103 as correction data, thereby accurately setting the charging voltage.

Next, the circuit of the strobe 2 shown in FIGS. 1 and 2 will be explained with reference to FIG. 4.

Figure 4 shows strobe 2 and C in this camera system.
FIG. 2 is a circuit diagram showing an example of a connection with a PUI and a strobe circuit. In the figure, when the second switch SW2 (not +) is turned on by pressing the release button two steps, the signal output to the output port 01 of the CPUI becomes H-L.Then, the transistor Q103 of the strobe circuit This causes transistor Q101Q to turn on.
102. Resistor RIOI, R102, step-up transformer T1
A well-known DC configured by connecting 01 as shown in the figure.
The oscillation operation of the /DC converter circuit is performed, and the main capacitor C101 is charged by the diode DIOI,
This is done via D102.

Resistor R, R capacitor C (main component 1 2' divides almost the same voltage as capacitor C101,
input to the A/D input port 11 of. As a result, C.P.
U1 can monitor the charging voltage of main capacitor C101 at any time. Here, the main capacitor Cl0I,) the trigger transformer T102.
Capacitor ClO3□Resistor R109, I GBT (I
nsulated Gate BipolarTran
sister) Q 104 forms a trigger circuit for the Xe tube 22. This IGBT Q104 is an element that can instantaneously control a large current depending on whether the gate voltage is H or L.

Next, a light emission control circuit for the Xe tube 22 will be explained. Resistors R104, R105, R109, IGBTQ104.
The capacitor ClO2 and the diode D104 are a voltage doubler circuit, that is, by applying a voltage twice the voltage across the main capacitor C101 between A- of the Xe tube 22 at the time of light emission, the light emission starting voltage of the Xe tube 22 is lowered. It is something to hold down.

Transistor Q105. Q106. Q107゜Q108
controls the gate of the IGBT Q104 in response to a light emission signal from the output port 02 of the CPUI or the output terminal C of the light emission Ql output means 7', which will be described later. Diode D103゜Resistance RIIO, constant voltage diode Z
D. Capacitor ClO4 is a power supply circuit for generating the gate voltage of IGBTQ104.

When the light emission signal from the output port 02 of the CPUI is not applied to the resistor R108, the transistor Q108. Q107
．． Q106 is off and the gate of IGBT Q104 is not biased. On the other hand, when a light emission signal is applied from output port 02 of CPUI, transistor Q
108°Q107. Q106 turns on and transistor Q
105 is turned off, IGB is connected through resistor R106.
The gate of TQ104 is biased to H. The capacitor ClO3 is charged in advance to the voltage across the main capacitor C101 through the resistor R104, and the capacitor ClO2 is similarly charged to the voltage across the main capacitor C101 through the resistor R104, R105,
The voltage across the main capacitor C101 is precharged through R109.

When IGBTQ104 is turned on, the charge in capacitor 0103 is transferred to trigger transformer Tl through IGBTQ104.
is discharged to the primary side of O2, thereby causing the same transformer Tl
High pressure is generated on the secondary side of O2 to ionize the Xe tube 22. At the same time, through the capacitor ClO2
The cathode of W 22 is lowered to -Volol, and as a result, a voltage of 2vc1o1 is applied across A- of the Xe tube 22, making it easier for the Xe tube 22 to emit light.

Then, when the Xe tube 22 starts emitting light, the emitting current discharges with the Cl0I-"Xe tube 22-D 104-C101, and the Xe tube 22 emits light.
When the light emission signal output from the output port 02 of the UI goes to L level, the transistors Q108, Q107. Q10
6 is turned off, and at the same time, transistor Q105 is turned on.

Therefore, the gate of IGBT QI04 is connected to transistor Q1.
It is shorted at 05 and IGBT Q104 is turned off.

Therefore, the capacitor ClO3 is connected through the Xe tube 22.
- The Xe tube 22 is charged with electric charge in an instant, and at the same time, the Xe tube 22 stops emitting light. Preparation for the next light emission ends at the same time as this light emission. That is, this circuit is ICBTQ10
4 is a circuit that has three functions: a trigger circuit for light emission, a voltage doubler circuit, and a main switch element for light emission.

A part of the above circuit is disclosed in the patent application filed in 1983 by the applicant.
No. 311,619.

The CPU is also provided with a terminal A1 for outputting a pre-light emission signal and a terminal B for manually inputting a light emission stop signal.

The circuit configuration of the detection element 7 for detecting the amount of light emitted during the pre-emission will be explained with reference to FIG. First, each burst of light emission from the Xe tube 22 is detected by a photodiode PDI, and its output is input to an integrating circuit composed of an operational amplifier OPI and a capacitor C2. Then, the output of the integrating circuit corresponding to the amount of light of the flash light is input to the comparator CP2, and a reference voltage Vrer1 is set, which indicates whether the amount of light has reached the reference value.
A comparison output is input to terminal B of the CPUI. In addition,
The integration operation of the integration circuit is started by the OFF operation of the switch element SWI01 connected in parallel to the capacitor C2. And switch SWI 01 is C
It is switched to the OFF state by an L level pre-emission signal output from terminal A of the PUI.

When the light emission amount detecting means 7 configured as described above detects the reference amount of light emission due to the flash light emission, in response to the comparison output, the light emission stop timing control circuit built in the CPU The flashing light is stopped.

Incidentally, it is also possible to adopt the circuit configuration shown in FIG. 6, which can further improve the pre-emission stop accuracy for the light emission detection means 7. This detection means 7' has a circuit configuration up to the output terminal of the comparator CPI.
is the same as The comparison output that changes to the L level when the light amount reaches the comparator CPI is amplified by the transistor Q1, and is amplified by the terminal C of the strobe circuit in FIG.
is input. When the terminal C becomes L level, the transistor Q108 is turned off, and the light emitting operation of the Xe tube is immediately stopped regardless of the CPU processing. Therefore,
This will improve the accuracy of when the light emission stops.

FIG. 7 is a flowchart of a photographing sequence of a camera having a flash light emitting device showing a first embodiment of the present invention. First, upon the 1st release, that is, when the release is pressed to the first step, photometry and distance measurement operations are performed in steps Sl and S2, and the respective data are temporarily stored in the CPUI. These stored data and camera-specific data, such as the distance between the optical axis of the taking lens and the flash tube, whether red-eye occurs, or
In step S3, a calculation and display is performed to determine whether or not there is a condition for red eye to occur due to brightness B, which is difficult to detect. Details of the process of "displaying red eye result" in step S3 are shown in FIG.

That is, in FIG. 8, in step S31, the output By from the photometric circuit is compared with the brightness B, and if Bv>B, it is determined that the pupil has already contracted sufficiently, that is, red eye will not occur, and a warning is displayed. is not carried out.

On the other hand, if Bv<B, the process proceeds to step S32, where a mode check is performed to see if the strobe is in a mode for emitting light, and if it is a non-emission mode, no warning is displayed, and if it is a light emitting mode, the process proceeds to step S33. In step 333, the subject distance data d is compared with a preset distance A, and if d<A, it is determined that red eye will not occur and no warning is displayed. If d>A, the process proceeds to step S34 to check whether or not the red-eye prevention mode is in effect, and if the red-eye prevention mode is not in effect, the process proceeds to step S35 to display a warning of the occurrence of red-eye.

By the way, considering that there is a limit to the distance that the strobe light can reach, instead of always displaying a warning when d>A as in step 333 above, when C> is shown in step 343 in FIG. It may be limited to d>A. Here, C is fixed data unique to the camera. The method of these calculations is detailed in Japanese Patent Application No. 63-298850 previously filed by the present applicant, so a detailed explanation will be omitted, but specifically, the numerical values are as follows.

jan 3° Here, Xl is the distance between the center of the strobe light emitting tube and the optical axis of the photographing lens, and f is the focal length of the photographing lens.

Returning to FIG. 7 again, in step S4 it is determined whether the 1st release is on or not. If the 1st release is not on, it is considered that the photographer has interrupted the shooting operation, and the process returns. If the 1st release is still on, the process proceeds to step S5, where it is determined whether the 2nd release is on, and if it is off, step S4. Wait until the 2nd release is turned on while repeating S5. 2nd
When the release is turned on, proceed to step S6 to check the conditions for red eye occurrence, that is, the settlement result in step S3,
If there is no red-eye generating condition, the process proceeds to step S9, where the lens is driven to the in-focus position, and the process further proceeds to step 31.8, where the shutter shutter is opened. On the other hand, if it is determined in step S6 that the red-eye occurrence condition is present, the process proceeds to step S7, where it is determined whether the "red-eye prevention mode" is in effect, and if it is not the red-eye prevention mode, the process proceeds to step S9. On the other hand, if the red-eye prevention mode is selected, the process advances to step S8, and a strobe recharging process in a subroutine to be described later is performed. Then, the first flash light emission is performed in step S1O, and then the lens is driven in step S11. Thereafter, the red-eye mode pre-flash is turned off a predetermined number of times by the steering knob S12.

A time chart in this case is shown in FIG.

Note that as shown in the flowchart in Fig. 10 and the time chart in Fig. 12, it is possible to perform the above-mentioned flash light emission and lens drive in parallel, but the CPU performs arithmetic processing etc. while the lens is being driven. Therefore, the high-voltage trigger when the strobe fires generates a large amount of noise that is input to the CPU board through lines and other patterns, potentially causing malfunctions and runaways. Therefore, the seventh
As shown in the figure and FIG. 11, during the CPUI calculation process,
It is better to avoid the risk of malfunction of the CPU 1 by avoiding the pre-emission operation.

In the pre-flash processing in step SIO and step S12, as shown in FIG. , the light emission amount detection means 7 starts detecting and integrating the light amount, and as mentioned above, when the predetermined reference light amount is reached, the comparison output of the comparator CPI is output to the terminal B of the CPUI, and the CPU responds to the output. Then, the output port 02 of the CPUI goes to the L level, and each flashing flash stops. Therefore, variations in the amount of light emitted due to variations in the light emission characteristics of the Xe tube 22, differences in circuit characteristics, differences in charging voltage, etc. are suppressed, and it is possible to perform bright light emission without excess or deficiency.

Also, when the above-mentioned detection means 7', which is a modification of the light emission amount detection means 7, is used, as described above, when the light amount reaches the reference value, the transistor Q108 immediately becomes inactive, and the Xe tube 22 also immediately stops emitting light. That is, as shown in the time chart of FIG. 14, the C terminal of the strobe circuit becomes L level when the above light amount is reached;
Since the input signal to the C terminal directly disables the transistor Q108, the light emission is quickly stopped. Therefore, the stopping precision is improved and the light emission becomes more accurate.

In this embodiment, as shown in the flowchart of FIG. 7, the flash light emission is not performed in response to the first press, but is performed in response to the second push. Generally, the time lag from the first press to the second press depends on the speed at which a person presses the release button. In addition, when you want to set the subject distance to 1 distance by pressing - degree and 1 step, and then change the camera angle to make the drawing more flexible, such as when locking the AF (autofocus), press the 1 step. It takes 5 to 10 seconds to press the second step. If the pre-flash is started from the first press, the total energy of the pre-flash will become too large, and in some cases, more energy than the main flash will be required for the pre-flash. Therefore, in this embodiment, by starting pre-flash in response to two steps immediately, the number of pre-flashes is stabilized, and as described above, the amount of light for each pre-flash is determined by apl. This realizes red-eye prevention pre-flash with little excess or deficiency of light quantity.

Next, charging control of the main capacitor will be explained. In the case of this embodiment, charging is started in response to the on operation or winding operation of the power switch (not shown) of the camera, but the charging processing routine of the flash light emitting device disclosed in the above-mentioned Japanese Patent Application No. 63-311619 Charging is performed in a routine similar to that shown in FIG. 23. That is, the resistance R,,R
2 (valley point in Figure 4) divides the voltage equivalent to the main capacitor and inputs it to the CPU's A/D port, and when the charging reference voltage reaches a predetermined value, the CP
Charging is stopped based on the judgment of U (see Fig. 24). Furthermore, if it is determined that the release button is pressed down to the second step during charging, charging is stopped regardless of whether or not the battery is uncharged (see FIG. 25).

Thereafter, in this embodiment, a strobe recharging process (see the subroutine of FIG. 15) is performed in step S8 after the red-eye prevention mode determination in the flowchart of FIG. 7. If the light emission is as small as a flash light, the energy of the light emission can be supplemented by this recharging. In other words, pre-emission can be performed with the conventional capacitor capacity as long as this recharging is performed. To describe this more specifically, the amount of light that can be emitted (GNo) is determined by the energy charged in the main capacitor, and the size of the main capacitor is determined by the amount of energy desired to be charged.

Therefore, if the total amount of energy to be charged is Et, the total amount of energy used in multiple pre-flashes is Ep, and the total amount of energy used in one flash is EIll, then in the conventional example El = Ep + Em, but in this example Now let's set Et=Em, and Ep can be replenished when pressing the second step. This is possible because it takes 0.7 to 0.9 seconds from the second stage suppression to the main flash due to the pre-flash, and the amount of flash light is small.

In addition, in the charging method of the flowchart of this embodiment shown in FIG. 7, the energy supplied by the DC/DC converter exceeds the energy released in the pre-emission due to the performance of the battery, and the charging voltage in step S8 is the main charge voltage. There is a possibility that the rated voltage of the capacitor will be exceeded. Therefore, the process in step S8 is not performed and the process in step S8 is not performed.
If the strobe recharging process of the subroutine shown in FIG. 15 is called in response to the flash flash signal at each flash flash in IO1 and step S12, and the main capacitor C101 is fully charged, the above procedure can be achieved. Problems can be resolved.

In this embodiment, after pressing the second step in step S5 of the flowchart of FIG. 7, the CPUI performs various calculation processes. Therefore, there is a possibility that the timing of performing the recharging in step S8 will be delayed. A modification of the charging method for the main capacitor C101 that solves this problem will be described with reference to the strobe circuit including the CPU shown in FIG. 17 and the flowchart shown in FIG. 18. In FIG. 17, the voltage division value Vc of the charging voltage by the resistors R, , R2 is the charging reference voltage V,
. , 3, the output Vo becomes H level, and the output VO is input to the charging voltage input port I2 of the CPUI and the OR circuit 0RIOI, respectively. The output of the output port 03 which instructs the start of charging of the CPUI is sent to the above-mentioned OR circuit 0RIOI. The output of the OR circuit is then connected to the DC/DC converter control transistor Q103. The other circuit configurations are the same as the strobe circuit shown in FIG. In the above circuit, at the beginning of charging, the output V of comparator CP3
O is at L level, and output port 03 of CPUI is at H level. Therefore, the output of 0R101 is H level, Q
103 is turned off and the DC/DC converter is stopped. After that, when the power switch is turned on, when the film is wound, or in response to a flash light instruction, the output port 03 of the CPU becomes L, Q103 turns ON, and D
C/DC converter operates. When the voltage divided by the resistor R1゜R2 reaches a preset voltage (reference voltage Vrcr3), the output of the comparator CP3 is inverted from L to H, and the output is transmitted to the CPUI and also to 0RIOI, Stop the C/DC converter. Thereafter, the CPU 1 detects the output of the comparator CP3 and changes the output of the output port 03 from L to H. With this configuration, even if the CPU reaches the specified voltage during arithmetic processing, the comparator CP3
Since the C/DC converter can be controlled, it is only necessary to detect when the specified voltage has been reached, and then change the output of output port 03 to the initial value H, which prevents the main capacitor voltage from rising too much. , charging voltage can be controlled with high precision. Moreover, the CPU can freely start and stop the oscillation of the DC/DC converter. The flow at this time is shown in FIG. Moreover, the above-mentioned output level of each person and the operating state of the converter have a relationship as shown in Table 1.

Table 1 The relationship between the charging state and the strobe light emission signal is shown in the time chart of FIG. 19.

Next, a flashlight emitting device showing a second embodiment of the present invention will be described. In this embodiment, a magnetically sensitive element is applied to the light amount detecting means for flash light emission, and the configuration of the strobe circuit including the CPU is shown in FIG. 20. Further, a circuit diagram of the light emission amount detection means 8 is shown in FIG. As shown in the strobe circuit of FIG. 20, the Hall element H1, which is a magnetically sensitive element, is arranged near the connection path between the Xe tube 22 and the main capacitor C101. Since the emission brightness of the Xe tube 22 is approximately proportional to its emission current, the emission current is detected by the Hall element H1 provided in the connection path.

The other circuit configurations are the same as the strobe circuit of the first embodiment shown in FIG.

As shown in FIG. 21, the light emission amount detection means 8 amplifies the output of the light emission current of the Hall element H1 using an operational amplifier OP3, and connects the output to the base of the transistor Q2. The collector current is integrated by an integrating circuit composed of an operational amplifier OP4 and a capacitor C2. Then, the output voltage of the integrating circuit corresponding to the amount of flash light is compared with a reference voltage corresponding to the reference amount of light by a comparator CP2, and the comparison output is inputted to terminal B of the CPUI. The integration circuit is instructed to start an integration operation by the switch element 101, and its circuit configuration is the same as that of the detection means 7 of the first embodiment.

When the light emission amount detection means 8 configured as described above detects a certain amount of light emission due to flash light, in response to the comparison output, the light emission stop timing control circuit built in the CPU The flashing is stopped every time.

Note that as a modification of the light emission amount detection means 8, which can further improve the accuracy of stopping flash light, it is possible to employ the circuit shown in FIG. 22. The circuit configuration of this modified example is such that a transistor Q3 is provided which makes the output of the comparator CP2 one level with respect to the detection means 8, and its output is connected to the C terminal of the strobe circuit shown in FIG. It is something. According to this modification, it is possible to control the timing of stopping the pre-flash directly by using a signal from the C terminal without going through the CPUI, thus improving the stopping accuracy and preventing excess or deficiency of the pre-flash. It will be further improved. Note that the details of the circuit operation are the same as in the case of the light emission amount detection means 7' described above.

In the second embodiment, a Hall element is used as the detection element, but it is of course possible to use other magnetic sensing elements.

In addition, the above-mentioned 1. In the flashlight emitting device of the second embodiment, as shown in the flowchart of FIG. 7, the strobe is recharged (step S8) after the second stage release operation and after the red-eye prevention determination. However, in the flashlight emitting device of the present invention, the strobe recharging is not necessarily an essential step, and the main capacitor C101
If the capacitance of the capacitor is sufficiently large, the capacitor can be charged in a processing routine in which the capacitor is charged in response to the turning-on operation of a power switch or the film winding operation.

[Effects of the Invention] As described above, the flashlight emitting device of the present invention detects the amount of light emitted by the detection means in response to the flashlight emission operation for pupil constriction, and receives the output from the flashlight emission control circuit. According to the present invention, the amount of light emitted from the pupil constriction light is controlled to a constant reference amount. Therefore, the amount of light emitted is less likely to change due to variations in flash tubes, circuits, capacitor charging voltage, etc., and has a sufficient pupil constriction effect, while also reducing power consumption. It is possible to provide a flashlight emitting device that has remarkable effects such as:

[Brief explanation of the drawing]

FIG. 1 is a block configuration diagram of a camera equipped with a flashlight emitting device showing a first embodiment of the present invention, FIG. 2 is a connection diagram of main parts of a strobe circuit of the flashlight emitting device shown in FIG. 1, and FIG. is a perspective view of essential parts showing the arrangement of light receiving elements of the flashlight emitting device shown in FIG. 1 above, FIG. 4 is a strobe circuit diagram of the flashlight emitting device shown in FIG. 1 above, and FIG. 6 is a circuit diagram of a detection means showing a modification of the light emission amount detection means of the above-mentioned FIG. 5; FIG. 8 is a flowchart showing details of step S3 in the flowchart of FIG. 7, and FIG. 9 is a flowchart showing a modification of step 533 in the flowchart of FIG. 8. , FIG. 10 is a flowchart showing a modification of the processing between step 87 and step 312 in the flowchart of FIG. 7 above, and FIGS. 13 is a time chart of the detection process of the light emission amount detection means of the flashlight emitting device shown in FIG. 15 is a flowchart showing the strobe recharging subroutine of the flashlight emitting device shown in FIG. 17 is a circuit diagram showing a modification of the strobe circuit of the flashlight emitting device shown in FIG. 1 above; FIG. 18 is a strobe circuit diagram showing changes in the DC converter control signal; A flowchart of a strobe charging subroutine for the circuit. FIG. 19 is a time chart of a flash light emission process when the strobe circuit according to the modification of FIG. 17 is applied. FIG. A strobe circuit diagram of the light emitting device; FIG. 21 is a circuit diagram of the light emission amount detection means of the flashlight emitting device of FIG. 20; FIG. 22 is a detection means showing a modification of the light emission amount detection means of FIG. 21; FIG. 23 is a flowchart of a strobe charging subroutine of a conventional flashlight emitting device. FIGS. 24 and 25 are time charts of charging voltage in the strobe charging process shown in FIG. 23. 1......CPU (control means including a light emission stop timing control circuit) 7.7'...Detection means including a light receiving element (
Light emission amount detection means) 8.8'...Detection means (light emission amount detection means) including a Hall element (magnetic sensitive element)

Claims (3)

[Claims] (1) In a flashlight device that performs a plurality of flashlight operations for pupil constriction and a flashlight operation for exposure, the flashlight emission amount detection means; 1. A flashlight emitting device, comprising: a control circuit that controls when to stop emitting a flashlight. (2) The flash light emitting device according to claim 1, wherein the detection means includes a light receiving element disposed near the flash tube. (3) The flash light emitting device according to claim 1, wherein the detection means includes a magnetically sensitive element disposed near a connection path between the flash tube and the main capacitor.