JPH06208159A - Stroboscopic device - Google Patents

Abstract

PURPOSE:To transmit the data on luminescence to a wireless stroboscope without adding a new member on the camera side by providing a control means performing the light emitting preparation of a light emitting means in response to the signal from a light receiving means. CONSTITUTION:A CPU 27, which calculates the received pulses and detects that the luminescence from an infrared ray emitting LED 21 is constituted of continuous pulses, performs the light emitting preparation of a stroboscopic circuit 26 when it detects that the luminescence from an object 28 is constituted of continuous pulses and judges that this luminescence is emitted by the range finding action of a camera 28. An external stroboscope 40 completing the light emitting preparation starts to emit light after it detects the stroboscopic luminescence of the camera 30. The camera 30 merely makes the normal photographing action and do not make a special action to operate the external stroboscope 40 at all. The external stroboscope 40 side enters the light emitting preparation posture by itself via the normal photographing action of the camera 30, and any camera making the above action can perform wireless stroboscopic photographing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flash device for a camera.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication (Kokai) No. 57-56830 discloses that a master strobe mounted on a camera side makes a preliminary light emission prior to the main light emission, and a sub-strobe measures the main light emission within a fixed time after the preliminary light emission. Is disclosed.

Further, Japanese Laid-Open Patent Publication No. 57-56831 discloses a wireless strobe for controlling the light emission of a sub-strobe by sending an optical signal related to the light emission timing from a dimming controller attached to the camera side and receiving the optical signal on the sub-strobe side. A device is disclosed. In addition, there is a so-called slave strobe that detects the emission of the main strobe as a change in external light and emits the sub-strobe.

[0004]

However, in Japanese Unexamined Patent Publication No. 57-56830, since the subject can visually recognize a small amount of light emission before the main emission, this is mistakenly recognized as the main emission or recognized by the subject. Even if you do not want to be done, you may be noticed before the actual shooting. Further, in Japanese Patent Laid-Open No. 57-56831, the wireless strobe cannot be used unless a dimming controller including a light emitting unit is added to the camera. Further, in the slave strobe system in which the change of the external light is used as the light emission start signal, there is a possibility that the flash is vulnerable to the change of the external light.

The strobe device of the present invention has been made in view of such a problem, and provides a strobe device capable of transmitting light emission data to a wireless strobe without adding a new member on the camera side. It is in.

[0006]

To achieve the above object, the strobe device of the present invention comprises a light emitting means, a light receiving means for receiving distance measuring light emitted from the camera body, and the light receiving means. Control means for preparing the light emission of the light emission means in response to the signal.

[0007]

That is, in the strobe device of the present invention,
The light emitting means prepares to emit light according to the distance measuring light emitted from the camera body.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 3 is a block diagram of a wireless strobe system according to an embodiment of the present invention. This system comprises a camera 30 and an external strobe 40. The camera 30 has an infrared light emitting LED 21 that emits infrared light consisting of continuous pulses to the subject 28 during distance measurement.
And a PSD 22 that receives the reflected light from the subject 28,
And a distance measuring circuit 23 for measuring the distance to the subject by the amount of light or by triangulation.

When measuring the distance of the camera 30, the external strobe 40 calculates the received pulse by the photodiode 24 which receives the reflected light of the infrared light from the subject 28, the photometric circuit 25 which measures the light by the amount of light. Infrared light emission LE
It is composed of a CPU 27 that detects that the light emission from D21 is composed of continuous pulses, and a strobe circuit 26 that emits strobe light in response to a signal from the CPU 27.

In the above structure, the CPU 27 detects that the light emitted from the subject 28 is composed of continuous pulses, determines that the light emission is due to the distance measuring operation of the camera, and emits light from its strobe circuit 26. Get ready. The external strobe 40, which has prepared for the light emission, detects the light emission of the strobe of the camera 30 and also starts the light emission itself. At this time, the camera 30 only performs a normal shooting operation and does not perform any special operation for operating the external strobe. The configuration of a camera with a built-in strobe as the camera 30 will be described below with reference to FIG.

The CPU 1 built in the camera body has a strobe 2, a display unit 3, a shutter control unit 4, a photometry circuit 5, a distance measurement circuit 6, a lens drive unit 7, and a mode setting unit 8.
Are connected. The CPU 1 is further connected with SW1 and SW2 which are turned on in response to the one-step depression and the two-step depression of the release button.

SW1 is turned on by pressing the release button one step.
Then, the CPU 1 operates the distance measuring circuit 6 and the photometric circuit 5 to store the information from each. When the camera and the strobe 2 are set to the flash photography mode by the mode setting means 8, the lens driving means 7 and the shutter control means 4 operate when SW2 is turned on by pressing the release button in two steps.
When it is determined from the information of the photometry circuit 5 that the strobe is necessary, the strobe 2 operates and the normal photographing operation is performed. The configuration of the slave strobe as the external strobe 40 will be described below with reference to FIG.

The strobe 11, which starts boosting when the power is turned on, stops boosting when it reaches a predetermined voltage by the control means 12 which monitors its charging voltage. Control means 1
2 activates the display means 15 for notifying the light emission permission when the voltage reaches another predetermined voltage lower than the voltage for stopping the boosting.

The AF infrared light receiving means 14 receives continuous pulses of distance measuring infrared light emitted by the distance measuring circuit operated by pressing the release button of the camera shown in FIG. Count the number. The infrared light pulse received by the AF infrared light receiving means 14 is differentiated and then simultaneously output to the light amount detection means 16 for detecting the start and stop of light emission.

The output of the light amount detecting means 16 to the control means 12 is prohibited during a period in which the signal processing means 13 counts the output of the light receiving means 14 a predetermined number of times and then waits for the pulse to be continuously emitted to end. . After the pulse that is continuously emitted is finished, the prohibition of the output to the light amount detection means 16 is released. When the strobe emits light while waiting for a fixed period of time to emit light from the built-in strobe of the camera, the light amount detection means 16 causes the control means 1 to coincide with the start and stop of light emission.
A signal is output to 2 and the strobe 11 starts and stops light emission. The operation of the camera after the release switch is turned on will be described below with reference to FIGS.

In response to the one-step depression of the release button, the CPU 1
01 stops the operation of the booster circuit 103 (DC / DC) for securing the operating voltage of the IC even when the voltage of the power supply drops (S1). This is to prevent erroneous determination due to noise when measuring a minute signal such as the next distance measurement or photometry. Next, temperature measurement is performed to obtain a correction value of the AFIC 106 having temperature characteristics in the IC itself (S2). After obtaining the correction value of the temperature characteristic of the AFIC 106, the AFIC 106 measures the distance by the active AF and performs the photometry for obtaining the exposure (S3, S4).

Next, a battery check by a dummy load is performed to determine whether power can be supplied to the actuator for driving the shutter (S).
5). If the battery check determines that the operation is inappropriate,
Here, even if the release button is entered and the release button is pushed further in, the second step is not accepted. Battery check O
After K, a strobe charge voltage check is performed to confirm whether the strobe can emit light or is fully charged (S6). When the light cannot be emitted, the display and notification for notifying that the battery is not charged are locked, and even if the light can be emitted, the light emission time is corrected to compensate for the insufficient light quantity before charging is completed. Exposure calculation is performed based on the measured values of the previous photometry and distance measurement (S7), and the input of the two-step pressing of the release button is waited (S8,
S9, S10). FIG. 6 shows a subroutine for distance measurement which is operated by the first release in FIG.
1 to ST8.

The AFIC 106 shown in FIG.
It is an IC that has a function to measure the distance to the subject by measuring the distance to the subject by receiving the amount of light reflected from the subject by emitting ED and IRED, and improving the measurement accuracy by repeating the light projection and light reception. However, the correspondence between the number of repetitions during one distance measuring sequence and the amount of received light and the projected distance is stored in the EEPROM 107 as adjustment data when the camera is manufactured.

When the distance measuring sequence is entered, the CPU 101 makes E
AFIC by reading the data from the EPROM 107
The operation amount of 106 is set, and the light amount value received in synchronization with the IRED projection is transmitted to the CP via the interface IC 104.
The operation of taking the subject distance into U101 and calculating the subject distance is repeated a predetermined number of times which has been previously stored. Usually, this number is 30
It is set to about 40 to 60 times at intervals of 0 μS to 400 μS. After the distance measurement is repeated a predetermined number of times, the lens extension amount for focusing is calculated and the distance measurement sequence ends. Steps S12 to S29 of the flowchart of FIG. 7 show the operation when the release two-step push is performed subsequent to FIG.

Based on the result of the above-mentioned exposure calculation, it is determined whether or not strobe light emission is necessary, and if necessary, the charging voltage is checked again. If it is equal to or higher than the light emission permission voltage but does not reach the stop voltage, the light emission time is reached. To compensate. If the voltage is below the light emission permission voltage, it is confirmed by the mode setting means 8 in FIG. 1 whether or not the strobe light emission mode has been released.

When the light emission mode is released, the shutter is set to the required shutter time, the lens is driven based on the distance measurement data to open the shutter, the second is counted, the shutter is closed and the lens is returned to the reset position, and the shutter is released. End the sequence.

If the previous charging voltage check is OK, after setting the shutter speed according to the flash firing,
The lens is driven, and then the shutter is opened and when a predetermined aperture value is reached, a light emission control signal is sent to the strobe, and after stopping the strobe light, the shutter is closed and the lens is reset. FIG. 8 is a block diagram of an external strobe used separately from the camera body, and FIG. 9 is a time chart showing its operation.

Main switch 20 for connecting the power supply
When 3 is turned on, the CPU 205 operates by the operation of the constant power supply regulator 204, and the CPU 205 receives an operational amplifier 206 for receiving and amplifying the infrared light for AF of the camera, a filter 207 for removing the infrared light component of the stationary light and the fluorescent lamp, and a waveform. A constant voltage is supplied to the power saving circuit of the shaping circuit 208, the one-shot multivibrator 209 for detecting that the infrared light pulse is continuously emitting, and the strobe light detecting circuit 210 for detecting strobe light emission of the camera.

The photodiode 211 is an infrared light photodiode for picking up reflected light from the subject of the AF infrared light LED of the camera, and the photodiode 212 is a stationary light LED for detecting strobe light emission of the camera. ing. The operation will be described below with reference to FIG.

FIG. 10A shows the light emission of the AF LED of the camera. The strobe that turned on the main switch 203 is in a state of waiting for a light reception signal from the LED 211, and
Waveform shaping circuit 20 for receiving continuous pulses of F infrared LED
The same pulse signal as B is output to 8 and sent to the CPU 205. The one-shot multivibrator 209 is set so as to stop the signal output after the input pulse signal has a predetermined delay time, and keeps updating the output C while the output B continues at a constant interval. However, if there is no next input within a predetermined time from the last pulse, the output C is inverted and the state returns to the steady state.

The CPU 205 receives the output C as a continuous pulse signal of AF infrared light. Photodiode 2
Reference numeral 12 is a photodiode for stationary light for detecting a rapid change in stationary light due to strobe emission of the camera as described above, and is converted into an output differentiated by the capacitor 213.
When the input of the photodiode 212 increases, a positive differential output is output to H, and when the input of the photodiode 212 decreases, a negative differential output is output to H. As a result, the transistor 215 is turned on when the flash light emission of the camera is started, and the transistor 216 is stopped when the flash light emission is stopped.
Is turned on, and signals are output to the outputs J and I and transmitted to the CPU 205.

The strobe boosting circuit 201 and the strobe light emission control circuit 202 have known circuit configurations, and the CPU 205
The output D of this turns on the transistor 217 and starts the oscillation operation. The voltage E obtained by dividing the voltage stored in the main capacitor 218 by the resistors 219 and 220 is used by the CPU 20.
Monitor at 5 and output D when charging to the specified voltage is completed
To stop boosting.

When the CPU 205 receives the I signal and inverts the output F, it turns on the thyristor 221 and the trigger coil 22.
A high voltage is generated at the output end of 2 and the Xe tube 223 starts to emit light. At this time, a predetermined voltage is applied to the gate of the IGBT 225 by the Zener diode 224 in advance and the energy of the main capacitor 218 is discharged through the Xe tube 223 so that the Xe tube starts to emit light.

Next, when the J signal is received, the CPU 205 inverts the output G and turns on the transistor 226 to turn on the IGBT.
By discharging the voltage applied to the gate of 225, the IGBT 225 is turned off and the Xe tube 223 stops emitting light. 10 and 11 are flowcharts showing the operation of the external strobe, and SP1 to SP14, respectively.
It consists of steps SM1 to SM18.

First, when the main switch is turned on, the CPU starts its operation and checks the charging state of the main capacitor. If not charged, charging starts. After the start of charging for detecting the first charge level, that is, so-called boosting abnormality, it is confirmed that the voltage can be reached in about 1 second, and if it is OK, charging is continued. After that, when the charging progresses to the second voltage level, which is 0.5 steps lower than the normal maximum amount of light emission and the light emission permission voltage, which is about 0.5 steps lower, the display indicating the light emission permission is turned on, and then the reflection of the AF infrared LED of the camera from the subject. Permits interruption of signals from the light receiving circuit that receives light. If an interrupt does not occur, the charging operation is stopped after charging to the stop voltage at which the maximum light amount is emitted. In the embodiment of FIG. 8, no output is output to the monitor terminal for the main capacitor voltage when the charging operation is stopped, so the charging voltage of the main capacitor is confirmed after a lapse of a predetermined time.

When the photographer presses the release button of the camera one step after confirming the light emission permission voltage or more, the camera uses the AF infrared LED for distance measurement at a predetermined duty ratio of several tens as shown in FIG. Repeat flashes. As mentioned above, A
The infrared light for F is projected onto the subject, and the photodiode for receiving infrared light of the external strobe receives the reflected light of the AF infrared light from the subject. The external strobe receives the first infrared light pulse and jumps to an interrupt routine to count the number of pulses. The pulse of the infrared light for AF varies depending on the camera, but it is projected repeatedly 50 to 60 times to improve the accuracy. It is determined that the pulse is artificial, that is, the AF projection of the camera.

The continuous pulse end signal, which is generated while receiving continuous pulses, is several tens from the last pulse.
If there is no next pulse within 0 μS, it is inverted, and accordingly, it is determined that the distance measurement of the camera has been completed, and main light emission acceptance is permitted to prepare for strobe light emission by the shooting operation of the next camera. When it is determined that the pulsed light input prior to this is AF infrared light of the camera, a display is provided to notify that the signal can be received on the strobe side. At the same time, a timer for operating the main light emission waiting time to a predetermined time is operated.

After that, if there is no input by main light emission,
After the display of the signal being received is turned off and the signal input is prohibited, the routine returns to the charging voltage confirmation routine to wait for the input of the infrared light for AF from the light receiving circuit again. This is one of the camera releases
You can also set it by checking in advance whether strobe reception is possible by pressing the button.

When the light receiving signal by the strobe light emission of the camera is received during the main light emission waiting state, the external strobe also outputs a light emission signal to start light emission and starts light emission. Furthermore, it detects that the flash of the camera has stopped emitting light and stops the emission of the external flash. Although not shown in the flow chart, since it is possible to confirm whether or not the light emission can be controlled by checking the residual voltage of the main capacitor immediately after the light emission is stopped, it is possible to notify the photographer by blinking the display.

[0036]

As described in detail above, in the strobe device of the present invention,

1. Since the external strobe side automatically enters the flash preparation system in the normal shooting operation of the camera, wireless strobe shooting can be performed with any camera that performs the same operation.

2. Since the normal shooting operation of the camera is used as a preparation signal for the wireless strobe, no new member or mechanism is required on the camera side to use the wireless strobe. 3. Since the preparation for light emission of the wireless strobe is prepared only by the distance measurement operation by the first release of the camera, it is possible to prevent erroneous light emission due to the influence of external light. 4. Prepare the flash for the wireless flash.
Since it is performed by the light emission of the ED, it is not necessary to notice the subject.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a built-in flash type camera.

FIG. 2 is a diagram showing a configuration of a slave strobe.

FIG. 3 is a configuration diagram of a wireless strobe system according to an embodiment of the present invention.

FIG. 4 is a configuration diagram for performing an operation after the release SW of the camera is turned on.

FIG. 5 is a flowchart for explaining the operation of the camera after the release SW is turned on.

6 is a diagram showing a subroutine for distance measurement in FIG.

FIG. 7 is a flowchart showing an operation when a release two-step push is performed.

FIG. 8 is a configuration diagram of an external strobe used separately from the camera body.

9 is a time chart showing the operation of the external strobe shown in FIG.

FIG. 10 is a flowchart showing an operation of an external strobe.

FIG. 11 is a flowchart showing an operation of an external strobe.

[Explanation of symbols]

21 ... Infrared light emitting LED, 22 ... PSD, 23 ... Distance measuring circuit, 24 ... Photodiode, 25 ... Photometric circuit, 26 ...
Strobe circuit, 27 ... CPU, 28 ... Subject, 30 ... Camera, 40 ... External strobe.

Claims (2)

[Claims] 1. A light emitting means, a light receiving means for receiving light for distance measurement emitted from a camera body, and a control means for preparing light emission of the light emitting means in response to a signal from the light receiving means. A strobe device characterized in that 2. The strobe device according to claim 1, wherein the distance measuring light incident on the light receiving means is reflected light from a subject.