JP2830369B2 - Flash device capable of multiple flashes - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flash device capable of performing multiple flashes for one photographing and capable of performing multiple flashes.

[Prior art] Conventionally, there has been a flash device of this type capable of multi-emission, and generally a battery power supply voltage is increased by a booster circuit (DC-
The voltage is boosted by a DC converter, etc., and the capacitor is charged with the boosted voltage, and the flash light energy of the flash is supplied from the capacitor. In the multi-flash mode, the frequency and the number of flashes can be set as appropriate.

[Problems to be Solved by the Invention] By the way, in this type of flash device, in the multi-emission mode, the emission frequency and the number of times of emission can be arbitrarily set, there is no problem where the emission frequency is low. However, in a high place, the number of times light can be emitted is limited by the capability of the booster circuit. Therefore, depending on the setting, the light emission of the set number of times may not be performed. In this case, the photograph will be different from the expected one.

In addition, if the number of times that light emission can be reliably performed at a high emission frequency is set as the upper limit, the number of times of emission can be reduced by the upper limit at a low emission frequency, even though more light emission is possible. It is limited and inconvenient.

The present invention solves the above-mentioned problem. By setting the number of times that light can be emitted reliably according to the emission frequency as the upper limit of the setting, it is possible to set the number of times of emission as much as possible, and to emit light of the set number of times. It is an object of the present invention to provide a flash device capable of performing multi-flash capable of reliably guaranteeing that a photograph different from expected in a multi-flash mode can be prevented.

Means for Solving the Problems In order to achieve the above object, the present invention provides a booster circuit for boosting a battery power supply voltage, a flash to which flash energy is supplied from an output of the booster circuit, and control of flash emission. In a flash device capable of performing multi-flash, which includes a control unit for performing multiple flashes for one shooting, and a unit for setting a multi-flash mode, a flash frequency and a number of flashes are set when the multiple flash mode is set. Setting means for setting the upper limit of the number of times of light emission that can be set according to the light emission frequency.

In the following embodiment, the flash microcomputer FLMC corresponds to the control means, and the microcomputer is provided with means for determining the upper limit of the settable number of times of light emission. Also,
A FREQ key S6 and a NUMB key S7 for inputting signals to the microcomputer FLMC are constituent elements of setting means for setting a light emission frequency and a light emission frequency, respectively.

[Operation] According to the above configuration, when the multi-flash mode is set,
Depending on the set frequency, the maximum number of times of light emission is automatically limited. That is, above a predetermined emission frequency, for example,
The mode (bulb) for continuous light emission cannot be set.

[Effects of the Invention] According to the present invention, when the multi-emission mode is set, the maximum number of times of emission is automatically limited according to the emission frequency. The number of times of the multi-light emission can be set as much as possible, and the set number of light-emissions can be surely assured, so that an expected photograph can be taken reliably.

Embodiment FIG. 1 is an overall circuit diagram of an embodiment of a camera system equipped with a flash device of the present invention, and FIG. 3 is a circuit diagram of an embodiment of a flash device.

In these figures, CB is the circuit of the camera body
LE is an interchangeable lens that is detachably attached to the camera body. FL is a circuit related to the flash device (hereinafter, referred to as a flash circuit, which is shown in detail in FIG. 3). The lens circuit LE and the camera circuit CB are connected to each other via connectors CN0 and CN1, and the flash circuit FL and the camera circuit CB are connected to each other via connectors CN2 and CN3. Work in conjunction.

FIG. 2 is a flowchart showing an operation of a microcomputer MCB (hereinafter, microcomputer is referred to as a microcomputer) which is a center of a control operation in the camera circuit CB.

Hereinafter, the above circuit configuration and its operation will be described with reference to the flowchart shown in FIG. In the following description, the signal name of a signal line may be used as the name of a terminal through which the signal enters and exits, and the high level and the low level of the binary level voltage are referred to as "H" and "L", respectively. Show.

In the camera circuit CB of FIG. 1, when the photometry switch S1 is closed at the first stage of pressing down a release button (not shown), the interrupt terminal IT of the microcomputer MCB falls to "L", and the microcomputer MCB Starts the operation from step 1 in FIG. 2 (hereinafter, step is denoted by #). In # 1, the transistor BT0 is turned on to supply power to the lens circuit LE via the protection resistor R, and also supply power to the display circuit DSP, the exposure control circuit EXC, and the photometry circuit LMC of the camera circuit CB.

Next, the microcomputer MCB performs a data fetch operation from the lens circuit LE in # 2. First, the interface circuit
The terminal CSL is set to “H” so that the IFC can perform a serial input operation from the lens, and then eight clocks for one byte are output to the terminal CKOB. At this time, since the terminal CSL of the interface circuit IEC is set to “H”, the lens circuit LE is activated, and the control signal is supplied via the control circuit CC based on the clock of the terminal CKOL corresponding to the clock from the terminal CKOB. Parallel data is read from the ROM. The parallel data is exchanged in series by the parallel-serial exchange circuit PS, output to the terminal SLD, and input to the serial input terminal SINB of the microcomputer MCB via the interface circuit IFC. The microcomputer MCB is this one
The byte data is stored in a predetermined built-in storage unit.

On the other hand, in the lens circuit LE, every time the output of one byte of data is completed, the control circuit CC sequentially updates the ROM address and continues reading. When reading data that changes during zooming of the zoom lens, the address of the ROM is specified by combining the code data output from the code plate ZC interlocked with the zooming operation and the data of the control circuit CC. In the case of a zoom lens, the data read by the camera in this manner include the open aperture value, the minimum aperture value, the amount of change in the aperture value due to zooming, the data of the focal length f of the photographing lens, and the photographing lens. This is the check data that detected whether or not the camera was worn.

When data acquisition from the lens circuit LE is completed,
The microcomputer MCB then proceeds to # 3, where the flash circuit FL
Move on to the data fetch operation from the side. Set terminal CSL to "L"
Then, the terminal CSF is set to “H”, and a “H” pulse of the time width TM0 is output from the terminal FMO. This pulse is input from the interface circuit IFC to the flash control circuit IC shown in FIG. 3 via the terminal ST3. When a signal is input to the terminal ST3 and it is detected that the time width of the signal is TMO,
The flash control circuit IC is ready for data output,
The terminal INT is set to “H” and the terminal W is set to “H”. As a result, the flash microcomputer FLMC (hereinafter referred to as the flash microcomputer) enters an interrupt processing mode and enters a data transmission mode.

Next, the microcomputer MCB on the camera side sets the terminal FCH to “H” so that the interface circuit IFC performs a serial input operation, and the clock is supplied to the flash control circuit I via the terminal ST3.
When sent to C, this control circuit IC outputs a clock to the terminal SCK. The flash microcomputer FLMC outputs data to the terminal SO in synchronization with this clock, and this is output to the terminal ST2. This serial data is read into the microcomputer MCB from the serial input terminal SINB via the interface circuit IFC. This data includes, for example, data indicating ON-OFF of the main switch S4 for power supply of the flash device, data indicating whether charging has been completed, and data relating to the guide number,
The data includes whether the flash is clipped on.

When the above-mentioned initial data capture on the flash side has been completed, preparations for actual operation are started in # 4 and thereafter. First, the terminals CSF and FCH are set to “L”, and the operation of the A / D converter built in the photometric circuit LMC is started (# 4). Then, data such as an exposure control mode, an exposure time, an aperture value, and an ISO sensitivity are input to the microcomputer MCB from the data output circuit DO (# 5), and then data from the photometric circuit LMC that has been subjected to the A-D exchange is input. (# 6).

The photometric circuit LMC includes a photometer for stationary light, an A / D converter for a photometric output of stationary light, and a photometer for flash light, and the terminal FSA of the flash photometer becomes “L”. This starts the integration of the photometric value.
When a value corresponding to the ISO sensitivity is reached, an "H" pulse for stopping light emission is output to the terminal FSP.

When the fetching of the A / D exchange data in # 6 is completed, it is determined in # 7 whether or not the flash is in the mounted state (ON state) based on the data from the flash side. If it is in the ON state, the calculation for flash photography is performed in # 8, and if it is not in the ON state, the calculation for steady light photography is performed in # 9. Next, at # 10, the calculated control value, mode, and the like are displayed on the display unit DSP. Next, at # 11, it is determined whether or not the interchangeable lens is mounted based on the check data. Here, if the lens is attached,
In # 12, the focal length f read at that time is reset, and if no lens is attached, the focal length f is left as it is,
In step # 13, data is sent to the flash circuit FL.

The data transmission operation in # 13 will be described first.
F is set to “H”, an “H” pulse of the time width TM1 is output to the terminal FMO, and is input from the interface circuit IFC to the terminal ST3. The flash control circuit IC receives this pulse,
When detecting that the time width is TM1, the terminal INT is set to “H”, the terminal R is set to “H”, and the flash microcomputer FLMC
Is in a data input operation state, a state is output in which the clock from the terminal ST3 is output to the terminal SCK, and a state is output in which the data from the terminal ST2 is output to the terminal SI. In the microcomputer MCB on the camera side, the terminal CSF remains at "H" and the terminal FCH remains at "L", the control aperture value and the type of shooting mode (P, A, S, M mode)
, And the ISO sensitivity and the focal length f are output in series one byte at a time. The interface circuit IFC outputs the clock to the terminal ST3 and the data to the terminal ST2, and these data are read into the flash microcomputer FLMC.

In # 14, it is determined whether or not the photometric switch S1 is kept closed, and if it is closed (ON), the process proceeds to # 19. #
At 19, a reset switch S3 that closes when the exposure control operation is completed and opens when the charge of the exposure control mechanism is completed.
Is determined. If the switch S3 is ON, the charging is not completed yet, so the flow returns to # 2 without determining the state of the release switch S2, and the same operation as described above is performed.

On the other hand, when the charging is completed and the reset switch S3 is turned off, it is next determined whether or not the release switch S2 which is closed at the second stage of pressing down the release button is turned on (# 20). ). Here, this release switch
If it is determined that S2 has not been turned ON, in step # 21, counting from the initial value of the power hold timer is started.
Return to

On the other hand, if it is determined in step # 20 that the release switch S2 is ON, an exposure start (start) signal is sent to the flash circuit FL in step # 22. In this operation, first, the terminal CSF is set to “H”, and an “H” pulse of the time width TM2 is output to the terminal FMO. This pulse is input to the flash control circuit IC via the terminal ST3, and upon detecting that the time width of the pulse input from ST3 is TM2, the control circuit IC sets the INT terminal to "H" and the REL terminal to "H". Flash microcomputer FLM
Notifies C that the release state has been entered, and the microcomputer FLM
Make a signal output from C. Next, microcomputer M
CB sets terminal CSF to “L” and terminal RELB to “H”,
An exposure control operation is performed by the exposure control circuit EXC. At this time, since the terminal RELB is at “H”, the interface circuit IFC transfers a signal input from the flash side via the terminal ST2 to the terminal FSA and a signal from the terminal FSP to the terminal ST3.
Output to

When the exposure start signal is input, the flash microcomputer FL
MC sets the terminal SO to “H”. This allows the control circuit
The terminal ST2 becomes “H” due to the movement of the IC. The closing signal of the X contact (Sx) (Fig. 1) is sent to the terminal ST1 of the flash microcomputer FLMC.
, The terminal SO is set to “L”. As a result, the terminal FSA changes from “H” to “L”. The photometric circuit LMC starts integration at the fall of the signal from the terminal FSA.

On the other hand, when the closing signal of the X contact (Sx) is input, the flash microcomputer FMC sets XETRIG to “H” and sets the xenon tube XE
To emit light. When the integrated value based on the integration in the photometric circuit LMC reaches a predetermined value, a light emission stop signal is output to the terminal FSP, input to the control circuit IC via the interface circuit IFC and the terminal ST3, and a light emission stop signal is output from XESTOP. Output, and the flash emission stops as described below.

The above exposure control operation is executed in # 23, and when this step ends, the microcomputer MCB returns to # 14. Here, it is determined again whether the photometry switch S1 is ON. If it is ON, the process returns to # 2 via # 19. On the other hand, switch S1 is
If it is turned off, the switch S3 is in the ON state, so that the transistor BTO is turned off in # 17, an interrupt to the terminal IT is enabled in # 18, and a series of operations is completed.

On the other hand, when the charging of the exposure control mechanism is completed and the photometry switch S1 is turned off while the reset switch S3 is off,
The process proceeds from # 14 to # 16 via # 15, and at # 16, it is determined whether or not the timer has overflowed (for example, 10 seconds have elapsed from the start of the timer). If an overflow has occurred, the operation proceeds to # 17, and the operation is terminated. If not, the operations of # 2 to # 13 to # 16 are repeated.

Next, the configuration and operation of the flash circuit FL will be described with reference to FIG.

The flash circuit FL includes a DC-DC converter 11 that boosts the battery voltage of the battery BATT, and a main capacitor that is charged by the boosted output and supplies the flash light energy of the flash.
C2, a flash control circuit IC connected to the circuit CB of the camera body via the connector CN3, a flash microcomputer FLMC that mainly controls the flash emission control and the charging voltage of the capacitor C2, and a xenon tube XE A flash control circuit 12 for controlling flash emission, a flash irradiation angle switching circuit 13, a display unit 14 for performing various displays, and a multi-switch S5 for setting a multi-flash mode for performing multiple flashes for one shooting. Operation unit with other switches
It consists of 15 and so on.

In this flash circuit FL, the main switch S4 is
When turned on, power is supplied to the flash microcomputer FLMC through the backflow prevention diode D1. The DC-DC converter 11 performs a boost operation while the terminal OSC is at “L”. The flash microcomputer FLMC detects the voltage level of the capacitor C2 by stepping down the voltage of the main capacitor C2 by resistance division of the resistors R1 and R2 and monitoring the voltage. The voltage of the capacitor C2 is equal to the maximum charging voltage V0 (for example, 33
0V) or less, the OSC terminal is set to "L" to operate the DC-DC converter 11, and when the voltage reaches the same voltage V0, the OSC terminal is set to "H" and the boosting operation of the converter 11 is stopped. As described above, the flash microcomputer FLMC enters the interrupt processing mode when the INT terminal becomes “H”, and enters the data transmission, reception, and light emission control modes according to the state of each terminal W, R, and REL. . The flow at the time of this interruption is shown in FIG. 4 (b) (described later).

The light emission control mode will be described.
When the TRIG terminal becomes “H” level, the terminal XETRIG of the light emission control circuit 12 becomes “H”, and the xenon tube XE starts emitting light. If the flash is not set to the multi-flash mode, the flash microcomputer FLMC terminal MULTI
Is "H" and the MXESTOP terminal is "L". As described above, when the flash stop signal is input from the terminal ST3 from the camera, the terminal X of the flash control circuit IC is output.
ESTOP becomes “H”, which causes the AND circuit 16 and OR circuit 17
, The light emission control circuit XESTOP becomes “H”, and light emission stops.

Next, the multiple light emission mode will be described. The multi-emission mode is one in which a subject is exposed several times on a single photograph by flash light, and can be used, for example, for analyzing sports forms.

When the multi switch S5 is turned ON, the flash microcomputer
The terminal MULTISW of FLMC becomes “L”. As a result, the flash microcomputer FLMC enters the multi-emission mode, and the frequency of the multi-emission and the number of times of emission can be set as described later. At this time, the shutter speed may be limited according to the number of light emission frequencies and the number of light emission times. This will be described below.

The flash microcomputer FLWC has the flash emission frequency,
Minimum shutter speed that can be set from the set value of the number of times
SSmin is calculated (SSmin = running time of shutter first curtain + (number of times−1) / frequency), and this data is transmitted to the camera by the above-described data communication. The camera controls the shutter speed SS based on this data. Further, when continuous light emission is set as the number of times of multi-light emission described later, the shutter speed of the camera is configured to be a valve.
In other words, the shutter speed of the camera from the flash side
By controlling the SS, it is possible to reliably emit light for a set number of times in one photograph.

Also, the following system can be configured. The shutter speed SS of the camera is transmitted to the flash by the above-mentioned data communication, and the flash sets the number of times of light emission and the frequency of the multi-shot within the limits of the number of times of light emission described below, based on this data.

Number of times <(SS-shutter first curtain running time) x frequency + 1
This makes it possible to surely emit light for a set number of times in one photograph.

Note that the flash frequency and the number of flashes may be sent from the flash to the camera to perform calculations on the camera side. Also,
When the camera is in the exposure time priority mode (S mode) or the manual mode (M mode), a warning may be issued if the shutter speed is set to be larger than the above SSmin. When the flash is mounted on a camera that does not have a function of processing the signal of SSmin, the number of times of light emission, and the data of the cycle, the value of SSmin may be displayed on the display unit of the flash.

In multi-emission, when the amount of light per light emission is determined, there is a relationship between the frequency and the number of times of light emission as shown in FIG. In the drawing, the area below the polygonal line is the settable area.

In other words, since the frequency of region 1 is high, the DC-DC converter
This is a region where the charge of 11 cannot catch up and emits light only by the energy stored in the main capacitor C2, and can emit light a fixed number of times regardless of the frequency.

The region 3 is a region where the frequency is low and the charging energy of the DC-DC converter 11 exceeds the energy consumption by the multi-light emission, and the light can be emitted until the battery runs out of energy regardless of the frequency.

Region 2 is a transition region between Region 1 and Region 3. Although the charging energy is lower than the energy consumption of multi-emission, energy can be injected several times, and the number of times of emission increases as the frequency decreases. As described above, when the amount of light emission per light necessary for actual use is determined, the number of light emissions is determined by the set frequency.

In FIG. 11, the battery BATT is assumed to be a battery (NiCd battery or the like) having a small change in performance due to a change in capacity. Alternatively, by checking the terminal voltage, the capacity of the battery can be grasped, and a graph can be written using the capacity as a parameter.

If the number of times of light emission can be freely set, an area where light emission cannot be performed at the set number of times occurs depending on the set frequency, and there is a possibility that shooting with multiple light emission cannot be performed as desired. Therefore, in the present embodiment, when the frequency is determined as described later, the number of times of light emission that can be set in accordance with the cliff shown in FIG. 11 is limited so that shooting with multiple light emission can be performed as desired.

Further, in this embodiment, the charge completion display is performed when the accumulated energy of the main capacitor C2 becomes maximum so that the number of times of light emission in the areas 1 and 2 can be as large as possible.

 Next, the operation of the multiple light emission will be described.

When the camera is released, the flash microcomputer FLMC enters the light emission control mode as described above. Now, the multi switch S5 is set to ON and the camera's X contact (SX)
Is ON, the flash microcomputer FLMC sets the terminal XETRIG to "H". As a result, the xenon tube XE starts emitting light. The flash microcomputer FLMC has a terminal MXESTOP to stop the light emission when the light emission amount of the xenon tube XE reaches the light emission amount per time required for actual use as described above.
To “H”. The timing of this stop is previously stored as time data after the flash microcomputer FLMC sets XETRIG to "H". At the same time, the terminal XETRIG is set to “L”.

Then, after an interval according to the set frequency described later, the terminal is set to XETRIG “H” again to start flash emission, and after a certain time, the terminal MXESTOP is set to “H”, and the terminal XETRIG
Is set to “L” to end flash emission at a constant light amount. The above operation is repeated a set number of times. The above is the operation of the multiple light emission.

The irradiation angle switching circuit 13 is a circuit that switches the flash irradiation angle so as to be optimal for the angle of view of the photographing lens based on the data of the focal length f of the photographing lens in the above-described camera-side data. (Panel) The relative position of 13b is controlled to set the flash irradiation angle.

Next, the operation of the flash microcomputer FLMC will be described with reference to the flowchart of FIG.

First, the overall flow of FIG. 4A will be described.
When the main switch S4 of the flash shown in FIG. 3 is turned ON,
Power is supplied to the flash microcomputer FLMC from its _VDD terminal, and the program starts. First, step #
In step 31, data necessary for flash operation, such as zoom data and display data, are initialized. Next, in step # 32, the voltage of the main capacitor C2 is monitored to perform a charge detection process. This detailed flow will be described later. Next, the panel position of the flash is moved according to the zoom data input from the camera in # 33 (when there is no input from the camera, the zoom data initialized in # 31). Next, in # 34, the flash controllable shooting distance range is calculated from the ISO sensitivity, aperture, and zoom data input from the camera, and the result is stored as distance data in the display memories 1, 2 in the flash microcomputer FLMC. (Not shown). Next, in # 35, processing by key operation (operation of the multi-switch S5, FREQ key S6, and NUMB key S7) is performed. This detailed flow will be described later. Next, in # 36, each process of turning on and off each display is performed according to the data in the display memory. After that, return to # 2,
Hereinafter, the same operation is repeated.

The flow at the time of interruption in FIG. 4 (b) has been described briefly above, but the “W processing” of # 44 is the same as that of # 3 in FIG.
The "REL processing" of # 45 is performed in the "flash data input" (data transmission mode) processing in step # 45, and the "exposure start signal is output to the flash side" (light emission control mode) in step # 22 of FIG. The “R processing” corresponds to the “data output to flash side” (data reception mode) processing of # 13 in FIG.

Next, the above-described charge detection processing will be described with reference to FIG. First, the voltage of the AD terminal is monitored, and the voltage Vc of the main capacitor C2 is detected (# 51). Then, it is determined whether or not the level of Vc is the full charge level V0 (for example, the maximum charge voltage 330 V) (# 52). If Vc is equal to or higher than V0, the OSC terminal is set to “H” (# 57), and the DC-DC converter Stop the step-up operation of 11. Further, the READY terminal is set to "L", and the charge completion display LED 18 (the mark 19 in FIGS. 7 and 9) is turned on (# 58). On the other hand, if the level of Vc is less than V0 in # 52,
The OSC terminal is set to “L” (# 53), and the step-up operation of the DC-DC converter 11 is started. Normal charging completion level V1
(# 54) is determined (# 54), and if less than V1, the READY terminal is set to "H" to turn off the charge completion display LED 18 (# 56). Vc level is V1
If it is less than V0, it is determined whether or not the multi-switch S5 is ON (# 55). If the multi-switch S5 is ON, the charging completion display LED 18 is turned off as described above (# 56). Light up (# 58).

As described above, when the multi-flash mode is set, the voltage of the main capacitor C2 becomes the normal charge completion level.
Even if V1 has been reached, the charge completion display is not performed, and the charge completion display is performed only when the full charge level V0, which is higher than that, is reached. Can be guaranteed.

Next, the key input processing will be described with reference to FIG.

First, it is checked whether or not the multi-switch S5 is ON (#
61). At this time, if the multi-switch S5 is OFF, the shortest distance data set in # 34 above is set in the display memory 1 (# 78), and the longest distance data is set in the display memory 2 (# 79). ). Further, the display memory 3 is set so that "DIST, m, ZOOM, mm" on the display unit 14 as shown in FIGS. 7 and 9 is turned on (# 80). On the other hand, if the multi-switch S5 is ON, the following operation is performed. First,
It is determined whether or not the FREQ key S6 has been input (the key has been pressed) (# 62), and if so, the FREQ data (frequency data) is updated (# 63 to # 67). In the example of this flowchart, every time the FREQ key S6 is pressed, the set frequency is changed in a cyclical manner from a loop of 50Hz → 10Hz → 5Hz → at 3 points. , The order may be reversed. If the FREQ key S6 has not been input, the next operation is performed without updating the FREQ data (with the previous setting).

Next, it is determined whether or not the NUMB key S7 has been input (#
68) When it is input, the NUMB data (frequency data) is updated in the same manner as the frequency described above (# 69 to # 74). In the example of this flowchart, as in the case of the FREQ key S6, NUMB
Each time the key S7 is pressed, the set number of times changes cyclically from the loop of 10 times → 5 times → (−−) →.
Here, “−−−” is a display meaning a mode in which multiple light emission is performed continuously during exposure of the camera without limitation of the number of times. The parentheses in the above mean that there are cases where display is possible and cases where display is not possible. In this example, when the above set frequency is 10 Hz or more, “−−”
(That is, continuous light emission) cannot be set, and when the set frequency is 5 Hz, “−−” (that is, continuous light emission) can be set.

As described above, when the multi-flash mode is set, the upper limit of the number of flashes is set in accordance with the frequency of the flash, so that the user can set the maximum number of flashes as much as possible, and the flash is surely guaranteed in the set range. And also
If the frequency is lower than the predetermined frequency, continuous light emission can be performed.

In this regard, if the number of times of multi-flash can be set arbitrarily, light emission can be guaranteed at a low frequency, but the number of flashes can be guaranteed at a high frequency due to the ability of the DC-DC converter 11 to charge the main capacitor C2. Is determined, and even if the number of times is set more than that, the light emission stops halfway, resulting in a different result from the expected photograph.

In addition, when the number of times that light can be reliably emitted at a high frequency is set as an upper limit, there is a disadvantage that the number of times of light emission is limited by the upper limit at a low frequency, although more times of light emission are possible. is there. On the other hand, in the present embodiment, the number of times that light emission can be surely guaranteed according to the frequency is set as the upper limit of the setting, so that a photograph different from expected is prevented beforehand.

As in the case of the frequency described above, the number of points that can be set may be further increased or the order may be reversed.

After the setting of the frequency (FREQ) and the number of times (NUMB) is completed as described above, the data is stored in the display memory 1,
2 (# 75, # 76), and the display memory 3 is turned on so that "FREQ, Hz, NUMB, REPS, ZOOM, mm" on the display section 14 as shown in FIGS. Is set (# 77).

FIG. 7 shows an example of the display unit 14 and the operation unit 15, and the display unit 14 shows a state where all displays are turned on. FIG. 8 shows an example of the display unit 14 shown in FIG.
(B) shows a display example at the time of multi-ON. FIG. 9 shows another example of the display unit 14 and the operation unit 15, and FIG. 10 shows an example of the display unit 14 of FIG.

In this way, the display contents are changed between multi-OFF and multi-ON, and the display part is also used for various displays, because the most necessary contents are displayed in each mode using the minimum display part That's why. In other words, it is necessary to display the frequency and the number of times of multi-emission at the time of ON, and since it is uncertain how many times the subject is irradiated, the distance data cannot be correct information. Is good. On the other hand, at the time of multi-OFF, it is not necessary to display these frequencies and the number of times, and it is necessary to display the flash light reaching distance.

The difference between the example of FIG. 7 and FIG. 8 and the example of FIG. 9 and FIG.
The display portion of the distance data at the time (shortest and longest data) is changed to the display of the data of the frequency and the number of times of the multiple light emission at the time of the multiple ON. On the other hand, in the latter, the display part by the display memories 1 and 2 is different from the former, and each display part of the distance data and zoom data at the time of multi-OFF is the multi-emission frequency and number of times at the time of multi-ON. It is to change to display.

Next, the relationship between the frequency and the number of times of the multiple light emission shown in FIG. 11 will be qualitatively described in detail with reference to the graph shown in FIG.

Now, one light emission energy is E, energy that can be used for light emission when charging is completed is E ₀ , charging speed (energy charged per unit time) is v ₀ , and light emission frequency is n.
(Integer) and the frequency is f, the combination of n and f that can emit light is obtained as follows.

n · E ≦ E ₀ + n · (1 / f) · v ₀ It is possible to emit light as long as the combination of n and f satisfies the relationship of Expression (1). In FIG. 12, a curve 11 corresponds to Expression (1), and a hatched portion is a light emission possible region. Note that the straight lines l2 and l3 are asymptote of the curve l1.

As is clear from the figure, if f ≦ v ₀ / E, the continuous light emission mode is possible. Also, even if f increases, E ₀ / E
One light emission is possible. The integer number of times smaller than E ₀ / E and closest to E ₀ / E can emit light even when f increases. Also, when f is changed stepwise, f smaller than v ₀ / E and closest to this is the limit of f at which continuous light emission is possible.

By storing in the memory whether or not light emission is possible for each combination, it is sufficient to read out the contents of the combination at the time of setting and determine whether or not light emission is possible. In such a case, a warning display may be performed. In addition, the settable range of f may be limited with respect to n, or the settable range of n may be limited with respect to f so as not to make a combination in which light emission is not possible.

Further, the light emission energy E for one time may be changed. In this case, the graph is switched according to the change of E.

When the voltage of the battery BATT decreases, the charging speed also decreases. Therefore, when the battery voltage decreases to a predetermined voltage, the graph to be used may be switched to a graph based on the charging rate for the predetermined voltage. Further, since the charging speed changes depending on the type of battery (difference in internal resistance), a graph may be stored in advance for each type of battery, and the graph to be used may be switched according to the type of battery.

[Brief description of the drawings]

FIG. 1 is an overall circuit diagram of a camera system equipped with a flash device according to an embodiment of the present invention, FIG. 2 is a flowchart showing the operation of a microcomputer of the camera, FIG. 3 is a circuit diagram of a flash circuit, and FIG. a) and (b) are flowcharts showing the entire flash-side microcomputer and an interrupt operation, FIG. 5 is a flowchart of a charge detection process, FIG. 6 is a flowchart of a key input process, and FIG. 7 is an example of a display unit and an operation unit. FIGS. 8 (a) and 8 (b) are diagrams showing display examples when the display unit is multi-OFF and ON, FIG. 9 is a diagram showing another example of the display unit and the operation unit, and FIG. 10 ( FIGS. 11A and 11B are diagrams showing display examples when the multi-OFF and ON states of the display unit in FIG.
FIG. 12 is a graph showing the relationship between the light emission frequency and the number of times. 11: DC-DC converter, FL: Flash circuit, FLMC
...... Flash microcomputer, XE ... Xenon tube, S5 ...
Multi switch, S6 ... FREQ key, S7 ... NUMB key.

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-63-199333 (JP, A) JP-A-61-159628 (JP, A) JP-A-63-199334 (JP, A) 4424 (JP, U) (58) Field surveyed (Int. Cl. ⁶ , DB name) G03B 15/05

Claims (1)

(57) [Claims] A booster circuit for boosting a battery power supply voltage;
A flash to which flash energy is supplied from the output of the booster circuit, and control means for controlling light emission of the flash;
Means for setting a multi-flash mode in which a plurality of flash fires are performed for one photographing. A flash device capable of a multi-flash mode includes setting means for setting a flash frequency and a number of flashes when the multi-flash mode is set. A flash device capable of multiple light emission, characterized in that the control means includes means for setting an upper limit value of the number of times of light emission that can be set according to the light emission frequency.