JPH02201430A - Flash emission device - Google Patents

Abstract

PURPOSE:To stably obtain the prevention effect of a red-eye by pressing a release button by two steps and executing pre-light emission. CONSTITUTION:When a first switch SW1 is turned on by pressing the release button by one step, a photometry circuit 101 and a range finding circuit 5 are operated by a CPU 1 and information from the respective circuits is stored. When a red-eye alarm display is given, a stroboscope 2 is switched to a red-eye prevention mode by a mode setting means 3 through the CPU 1 and the stroboscope 2 is once emitted a little light for contracting the pupil, first, when a second switch SW2 is turned on. Next, a lens is driven to a focusing position by a lens driving means 6. The opening and closing operation of a shutter is executed by the actuation of a shutter control means 4 after the pre-light emission and the stroboscope 2 is emitted light for exposure during the opening operation. By always making timing constant in such a way, the red-eye is stably prevented from occurring.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a strobe that can prevent the so-called red-eye phenomenon in which the eyes of a subject appear red when the subject is photographed using a flash light emitting device, and a strobe using the same. Regarding the photographic equipment used.

[Conventional technology]

As shown in Japanese Patent Publication No. 58-48088, an apparatus is known in which the pupil is constricted using a preliminary irradiation means such as a lamp before a strobe shot, and then the strobe is emitted to take an image.

[Problem to be solved by the invention]

In the above conventional technology, when the release button is pressed down about halfway (hereinafter referred to as 1-step press), the pupil constriction lamp is pre-irradiated for a certain period of time, and when the release button is pressed down to the final range (hereinafter referred to as 2-step press), (abbreviated as ) shutter opening operation and flash bridge type strobe light emission.

However, the time from the first press to the second press varies depending on the user, photographing conditions, etc.

That is, the timing from the end of preliminary irradiation to the start of photographing is inconsistent, and as a result, prevention of the red-eye phenomenon becomes unstable.

A first object of the present invention is to ensure that the above-mentioned timing is always constant, thereby stably preventing red-eye.

A second object of the present invention is to provide a camera system with a built-in CPU that stabilizes the operation of the CPU by prohibiting strobe light emission while the CPU is processing calculations.

A third object of the present invention is to reduce the size of the strobe's main capacitor and shorten the charging time by activating the strobe's DC/DC converter in response to the start of preliminary light emission for pupil constriction. The object of the present invention is to obtain a flashlight emitting device that can be used to measure time.

A fourth object of the present invention is to provide a flashlight emitting device that can warn the user in advance that red eye is likely to occur during normal flashlight photography.

[Means and effects for solving the problem] As shown in Figure 1, the CPU built into the camera body has a photometry circuit 1.
019 Display means 102I strobe 2. Mode setting means 3
．． Shutter control means 4, distance measuring circuit 5. Lens driving means 6
is connected. Further, connected to this CPU are a first switch SWI, which is turned on by pressing the release button one step, and a second switch SW2, which is turned on by pressing the release button two steps.

In addition, when connecting the CPUI and strobe 2, as shown in Figure 2, the output voltage of the main capacitor of the strobe is input to the A/D input terminal of the CPUI via the connection circuit of resistor RI + Ri + capacitor CI. It looks like this.

Further, an EzPROM 201 is connected to this CPU 1.

First, when the first switch SWI is turned on by pressing the first step of the release 20, the CPU first controls the photometry circuit 101.
, the distance measuring circuit 5 is operated and information from each is stored. When the camera and strobe 3 are set by the mode setting means 3 to flash photography mode and normal flash mode (mode that does not perform preliminary flash for pupil constriction), predetermined values (for example, the optical axis of the photographic lens and the strobe It calculates whether or not there are conditions for red eye to occur based on the distance #) from the flashlight emitting tube and the subject distance from the distance measuring circuit 5, and when there is a possibility of red eye occurring, a red eye warning is issued by the display means 102. let If the red-eye warning is not displayed, press the release button further to turn on the second switch SW2, and the lens drive means 6, shutter control means 4, and strobe light 2 will operate to perform normal photographing operations. It will be done. 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, when the second switch SW2 is turned on, the strobe 2 emits a small amount of light once for pupil contraction.Then, the lens is driven to the in-focus position by the lens driving means. Upon receiving this drive end signal, the strobe 2 again repeats a small light emission multiple times for pupil contraction (the previous small light emission is hereinafter abbreviated as pre-flash). After the end of this pre-flash, the shutter control means 4; Strobe 2 works.

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 R, , R□ and input to the A/D input port of the CPUI. , is converted into a digital signal, and when it reaches a preset value, the operation of the DC/DC converter of the strobe 2 is stopped. Here, the correction for the variation in the resistance values of the resistors R, RR is E"FR
By storing the correction data in the OM 201, the charging voltage can be set accurately.

〔Example〕

FIG. 3 is a flowchart showing one embodiment of the present invention. First, light metering and distance measuring operations are performed as the release button is pressed, and each data is stored. Based on these data and camera-specific data (for example, the distance between the optical axis of the photographing lens and the flash tube, the brightness β that does not cause red eye or is difficult to cause red eye), calculates and displays whether or not the conditions are such that red eye occurs. As shown in Figure 3 (^), this calculation display first compares the output βT from the photometric circuit with the brightness β,
If βT>β, it is determined that the pupil has already contracted sufficiently, that is, red eye will not occur, and no warning is displayed.A mode check is performed to see if the mode is set to emit the strobe in the 0th order, and the mode is set to non-emission mode. If so, the warning display will not be displayed.6 Next, the subject distance data d will be compared with the predetermined distance A, and if d<A, it will be determined that red eye will not occur and the warning display will not be displayed. , if d>A, it next checks whether or not it is in red-eye prevention mode, and if it is not in red-eye prevention mode, a red-eye warning is displayed.Please note that there is a limit to the distance that the strobe light can reach. Considering this, instead of always displaying a warning when d>A, it is possible to display <C> as shown in Figure 3 (B).
It may be limited to d>A, where C is fixed data specific 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.

xI: Distance between the center of the strobe light tube and the optical axis of the photographing lens f: Focal length of the photographing lens Returning to Fig. 3, when the SW dew is turned on by pressing the release button two steps, first Check the calculation result after pressing the release button one step to confirm whether the conditions are such that red-eye will occur).If the conditions are not met, drive the lens to the in-focus position, open the shutter, and fire the strobe for shooting (see below). It is abbreviated as main emission.

), close the shutter, cancel the red-eye warning (even if the red-eye warning has been issued, cancel it and return to the initial state), wind the film, and return.On the other hand, if the red-eye condition is present, first switch to the red-eye prevention mode. If it is in red-eye prevention mode, first perform a pre-flash once. (Refer to the time charts in Figures 4 and 5.) After that, the lens is driven. However, while driving this lens,
Pre-emission is not performed, but pre-emission is performed again multiple times at predetermined intervals after lens driving is completed.

This can be done by pre-flashing in parallel with the lens drive as shown in Figure 3C2 Figure 5, but the CPU is performing calculation processing etc. while the lens is being driven, and the high-pressure trigger when firing the strobe may have a large This may become noise and be input to the CPU board through lines or other patterns, causing malfunctions and runaways. Therefore, as shown in Figures 3 and 4, the pre-flash operation is not performed during CPU calculation processing. It is better to avoid the risk of CPtJ malfunction by avoiding this.

Further, in the present invention, as shown in the flowchart of FIG. 3, the pre-emission operation is not performed in response to the first press, but is performed in response to the second press. In general, the time lag from pressing the first step to pressing the second step depends on the speed at which the person presses the release button, and in AP lock, etc., the distance to the subject is measured by pressing the first step at -degrees, and then When changing the camera angle to freely draw images, etc., it takes 5 to 10 seconds to press the first step to the second step, and if the pre-flash starts from the first step, the total energy of the pre-flash will be reduced. If it becomes too large and stale, more energy will be required for the pre-emission than for the main emission.

Therefore, this proposal reduces and stabilizes the total energy of the pre-flash by starting the pre-flash in response to the second press, and also prevents red eye since the time from the second press to the shutter opening is approximately constant. The effect will also be stable.

When the red-eye prevention pre-emission continues for a predetermined period of time and ends, the shutter starts to open, and then the strobe main emission is performed and the shutter is closed at r8A.

When the shutter is closed, the camera is wound for the next shot and returned.

Figure 6 shows the connection between the strobe and CPU of this system.
and an example of a strobe circuit.

When the switch SW is turned on by pressing the second step, the CP
Signal 0 from U. becomes H-+L, Q103 turns on, oscillation occurs as is known, and capacitor C1
Charging to 01 is performed.

Resistance Rr, R! divides almost the same voltage as that of the capacitor C101 and inputs it to the A/D terminal of the CPU. Here, C101 is a main capacitor, TlO2 is a trigger transformer, and T102. C103, R109Q1
04 forms a trigger circuit. Q104 is I
G B T (Insulated Gat)
It is a device that can instantaneously control a large current by setting the gate voltage to H.

R104, C102, R105, D 104. R10
9, Q 104 is a voltage doubler circuit, that is, when emitting light,
By applying a voltage double the voltage across 0101 to A-K of the e-tube, the emission starting voltage of the Xe-tube is kept low. Q105. Q106. Q10? , Ql
oB receives the light emission signal from the Ot terminal of CP (J) and controls the gate of Q104.D1
03. R109°Zb and ClO4 are a power supply circuit for generating the gate voltage of Q104.

When no signal is generated at R108, Q108. Q
10? .

Q106 is OFF and the gate of Q104 is not biased.

CPU 0! When a light emission signal is generated from the terminal, Q10
B, Q 107. Q106 turns ON and Q10
5 is turned off, and the gate of Q104 is biased to H through R106. ClO3 is previously charged to the voltage of C101 through R104,
ClO2 becomes C through R104, R105, R109
It is precharged to 101 voltage.

When Q104 turns ON, the charge of 0103 becomes Q104
is discharged through the primary side of TlO2 to generate high pressure on the secondary side of TlO2 and ionize the Xe tube. At the same time, connect the cathode of the Xe tube to -v e through C102.
As a result, A-K of the Xe tube has 2
V-+. A voltage of , is applied, making it easier for the Xe tube to emit light. Then, the Xe tube starts emitting light, and the emitting current is C101 → X e → D 104-T
h C101 is discharged to cause the Xe tube to emit light. After that, when the 0□ light emission signal disappears from the CPU,
Q 108i Q 107. Q106 turns off,
At the same time, Q105 is turned ON. Therefore, the gate of Q104 is shorted by QI05, and Q104 is turned off. Therefore, C103 is instantly charged with an electric charge through the Xe tube, and at the same time, the Xe tube stops emitting light. Preparation for the next light emission ends at the same time as this light emission. Therefore, in this circuit, Q104 has three functions: a trigger circuit for light emission, a voltage doubler circuit, and a main SW element for light emission.

A part of the above circuit is disclosed in the patent application filed in 1983-311 filed by the present applicant.
Details are given in No. 619.

Next, the charging control portion will be explained based on FIGS. 3(0) to 3(G) and FIGS. 6 to 9.

In the aforementioned Japanese Patent Application No. 63-311619, this is done using a conventional charging control system.

That is, as shown in FIG. 3(D), the power switch (
Charging starts when the resistor (not shown) is turned on, and the resistor R+,
R! (See Figure 2) divides the voltage equivalent to the main capacitor and converts it at the A/D terminal of the CPU.
When a predetermined value is reached, the CPU determines and stops charging. Also, if it is determined that the release button has been pressed two steps during charging, charging will be stopped regardless of whether or not it is uncharged (see Figure 7).After that, if charging is completed or charging is not completed but the amount of light is emitted, pre-flash, Lens drive, shutter open 8 flashes, shutter closed 2 times, recharge, (8th
(See figure) However, if we consider that this pre-emission is to be performed, the capacitance of the main capacitor will increase by the amount of pre-emission, and the time required to charge this capacitor will also become longer.

For this reason, in this embodiment, recharging is started in response to two-step depression of the release button.

(See FIGS. 3(F) and 9) As a result, if the light emission is as small as the amount of pre-light emission, the light-emitting portion can be covered by this recharging. That is, as long as the conventional capacitor is used and it is recharged, pre-light emission can be performed, and the problems of the above-mentioned prior application can be solved.

To put this more specifically, it is light that can emit light! 1(G
No.) is determined by the energy to be charged to the main capacitor, and the size of the main capacitor is determined by the amount of energy you want to charge.

Therefore, the total amount of energy to be charged is ELI, the total amount of energy used in multiple pre-flashes is E, the total amount of energy used in main flashes is E, and in the above prior application Et-E, 10E. , in this example E,
-E means to keep it closed, and E means to replenish when pressing the second step. This is possible because it takes 0.7 to 0.9 seconds from the second press to the main flash due to the pre-flash, and the amount of the pre-flash is small. However, with the method shown in Figure 9, depending on the nature of the battery, the energy supplied by the DC70C converter may exceed the energy released during pre-emission, potentially exceeding the rated voltage of the main capacitor. . In this case, the DC70C converter may be started and stopped in response to the pre-emission signal.

Note that the CPU must perform various arithmetic operations after the second press, and the timing at which the charging control sequence can be performed may become longer. In this case, the configuration shown in FIG. 3 (G), FIG. 1θ, and FIG.
, and the charge signal output terminal of the strobe, and the output of this comparator OP is connected to the output terminal 0. and OR circuit 0RIOI
It is connected to the strobe's DC/DCC/actuator control transistor Q103 via the transistor Q103. In the above configuration, first the outputs of the comparators OP, OP, C
The output of the PUI is H. Therefore 0RIOI
The output of H2Q 103 is OFF and the DC70C converter is stopped. After that, when a power switch (not shown) is turned on, the output terminal O1 of the CPU becomes L, Q103 is turned on, and the DC70C converter is activated. When the voltage divided by the resistors R,, R, reaches a preset voltage (reference voltage), the output of the comparator OP is inverted from L to H, and the output is transferred to CP.
Notify the UI and also notify the 0RIOI, DC70
Stop the C converter. After that, the CPUI detects the output of OP and 0. change the output from L to H. With this configuration, even if the CPU reaches the specified voltage during calculation processing, the DC/DC converter can be controlled by the OP, so it will only detect that the specified voltage has been reached, and later output 01. It is sufficient to change the voltage to the initial value H, and the voltage of the main capacitor will not rise too much.
Can be controlled with 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. 3 (G), and these are summarized as shown in Table 1.

Table 1 [Effects of the Invention] As described above, according to the present invention, (1) By pre-emitting light by pressing the release button in two steps, the effect of preventing red eye can be stably obtained.

(2) Since pre-emission is not performed while the CPU is calculating, a trigger signal for pre-emission is not generated during the CPU's calculation, and malfunction of the CPU can be prevented.

(3) By issuing a red-eye warning in response to the first press of the release button, it is possible to prompt the user to change the mode when the setting mode is not red-eye mode, thereby preventing failure.

(4) By performing pre-flash in response to the second press of the release button, the pre-flash can be covered by recharging, making it possible to downsize the main capacitor and shorten the charging time.

This produces the following effects.

[Brief explanation of the drawing]

1 and 2 are block diagrams showing an overview of the present invention, FIG. 3 is a flowchart showing an embodiment of the present invention, and FIG.
Figures (A) to 3 (G) are flowcharts showing modifications of the above embodiment, Figures 4 and 5 are time charts showing an embodiment of the present invention, and Figure 6 is a flowchart showing a modification of the above embodiment. An example circuit diagram, FIG. 7, and a conventional example time chart diagram, FIG. 8. FIG. 9 is a time chart diagram of an embodiment of the present invention, FIG. 10 is a circuit diagram of another embodiment of the present invention, and FIG. 11 is a time chart diagram of the above embodiment. l・・・-・・ CPU 2・・−・・
...Strobe 3...Mode setting means 102
...---Display means SW1...---Switch SW that turns on by pressing the first step!・・・・・ Switch Xe that is turned on by pressing the second step −・・−・・・Flashlight-emitting Yukio 1 Ward No. 33 (A) Figure 3 (B) Figure 3 (E)

Claims (4)

[Claims] (1) In response to pressing the first step of the shutter release member, at least a photometering operation and a distance measuring operation are performed, and in response to pressing the second step, multiple flashing operations are performed for pupil constriction. A flash light emitting device characterized in that a shutter is opened and closed immediately after the light emission ends, and one flash light emitting operation is performed for photographing during this opening and closing operation. (2) A CPU that controls the exposure operation, and a CPU that responds to the camera's release signal and fires multiple flashes for pupil constriction until just before the shutter starts opening, and after the shutter starts opening, the CPU 1. A camera system comprising: a flash light emitting device configured to emit a flash light once as a flash, and the flash light emitting for pupil light constriction is prohibited during calculation by the CPU. (3) DC that charges the strobe capacitor
/DC converter, in response to the camera's release signal, fires multiple flashes for pupil constriction just before the shutter starts opening, and fires one flash for photographing after the shutter starts opening. In a flash light emitting device having a light emission control means for controlling the DC/D light emission in response to the release signal or the flash light emission signal,
A flash light emitting device characterized in that a C converter is changed from a stopped state to an activated state. (4) Red-eye detection means for detecting whether or not the subject is a subject that causes red-eye phenomenon; Display means for displaying a warning based on the output of the red-eye detection means; A switching means is provided for switching between a red-eye prevention mode in which flash photography is performed in which the red-eye phenomenon is prevented by causing the flash to emit light, and a normal flash mode in which the flash is not emitted before the shutter opening operation. A flash photography device characterized in that a display means is activated when an output is output from the detection means.