JPH11190872A - Optical transmitter and flash control system using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce energy required for transmission by controlling emitted light quantity of a flash emitting means according to quantity of information to be transmitted, and to prevent mis-emitting (transmission leakage) caused by too much decrease in a condenser voltage during transmission. SOLUTION: A transmitter microcomputer 109 reads a setting of a setting means 110, and sets IMAX and transmission data as emitted light quantity transmission data according to the number of read emitted light. Next, the transmitter microcomputer 109 processes the charged voltage of a main capacitor 103 by A/D conversion, and reads it. Next, the set IMAX outputs emission intensity data for setting from the transmitter microcomputer 109 to a DA converter 114. Thus, the transmitter transmits luminescence mode, emitted light quantity, that is, emitting, non-emitting of a discharge tube 105 to a receiver as a digital data of 1 or 0. And, an emission intensity of the optical transmission pulse is adjusted by setting the power output of DA converter 114 according to the number of emitted lights of the receiver set by the setting means 110.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical transmission device for transmitting information by generating an optical pulse using flash light emission, and further to a slave flash device based on information from the optical transmission device (master flash device). The present invention relates to a flash control system for controlling light emission of a device.

[0002]

2. Description of the Related Art Conventionally, a system for controlling light emission of a slave flash device using light emission of a master flash device has been proposed in Japanese Patent Laid-Open No. 7-43789. This system is used for camera photography and the like, and controls the light emission time of the master flash device according to the distance to the subject.

[0003]

However, when data such as the light emission state and the light emission amount is transmitted to the slave flash device using digital data of 0 and 1 due to light emission and non-light emission of the master flash device, especially light emission is required. If the number of slave flash units to be used increases, the amount of data increases, so that the capacitor stored energy for flash emission in the master flash unit is also consumed a lot, and the capacitor voltage may drop too much during transmission, resulting in light emission (transmission) failure. . In addition, since a large amount of time is required to charge the capacitor after transmission is completed, for example, there is a problem that it is inconvenient to perform continuous light emission.

[0004]

Therefore, in the first invention of the present application, the amount of information to be transmitted (for example, the number of light emitting devices of the slave flash device) And a light emission control means for controlling the light emission amount (light emission intensity, light emission time, etc.) of the flash light emitting means in accordance with the light amount and the information amount depending on the light emission mode.

According to a second aspect of the present invention, in a light transmitting apparatus for transmitting information using light emission of a flash light emitting means which emits light by using electric energy charged in a capacitor, detection of detecting a charged state of the capacitor is performed. Means and light emission control means for controlling the light emission amount of the flash light emission means in accordance with the state of charge detected by the detection means.

Further, according to a third aspect of the present invention, in a light transmitting apparatus for transmitting information using light emission of a flash light emitting means which emits light using electric energy charged in a capacitor, detection of detecting a charged state of the capacitor is performed. Means and light emission control means for controlling the light emission amount of the flash light emitting means in accordance with the state of charge detected by the detection means and the amount of information to be transmitted.

In the first and third inventions, when the total number of flashes of the flash light emitting means differs according to the amount of information to be transmitted, the amount of light emission of the flash light emitting means is controlled according to the total number of flashes. You may make it.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIG. 1 shows a flash control system for a camera according to a first embodiment of the present invention. FIG. 1A shows a master flash device (hereinafter, referred to as a transmitter) of a camera system that performs optical communication using flash and wirelessly controls a slave flash device, and FIG. Hereinafter, this is referred to as a receiver).

<< Transmitter >><Structure of Transmitter> The structure of the transmitter will be described with reference to FIG. 101 is a battery as a power supply, 102 is a booster for boosting the voltage of the battery, and 103 is a main capacitor for storing the output of the booster. An existing trigger circuit 104 excites the discharge tube 105 to emit light, and is a microcomputer (hereinafter referred to as a transmitter microcomputer) 10 on the transmitter side.
9 is connected to the output terminal TRI. Reference numeral 105 denotes a discharge tube (transmission flash light emitting unit) for converting electric energy of the main capacitor 103 into light, and reference numeral 106 denotes a light emission control unit for controlling light emission of the discharge tube 105. Reference numerals 107 and 108 denote resistors for dividing the charging voltage of the main capacitor 103, and the voltage dividing point is connected to the AD input terminal of the transmitter microcomputer 109.

The transmitter microcomputer 109 processes each operation of the flash device such as light emission control, light emission amount, and setting of the light emission mode. Reference numeral 110 denotes a light emission amount and light emission mode setting unit. 1
Reference numeral 11 denotes a charge completion display LED that indicates that the charge voltage of the main capacitor 103 has reached the light emission enabling voltage, and is connected to the open drain port of the transmitter microcomputer 109. Reference numeral 112 denotes a resistor connected between the power supply and the LED 111. Reference numeral 113 denotes display means for displaying the state set by the setting means 110. Reference numeral 114 denotes a DA converter, which outputs a DA output to a non-inverting input of a comparator 116 in accordance with data received from DA_OUT of the transmitter microcomputer 109. Reference numeral 118 denotes a light emission amount monitoring unit that receives light emitted from the discharge tube 105 and outputs a voltage corresponding to the light emission intensity. Note that the light emission amount monitoring means 118 is provided by the comparator 1
16 inverting inputs.

Reference numeral 116 denotes a comparator whose output is AN
It is connected to the D gate 117. Reference numeral 117 denotes an AND gate. The inputs other than those connected to the output of the comparator 116 are connected to the output terminal STSP of the transmitter microcomputer 109, and the outputs are the emission control means 106 and the transmitter microcomputer 109.
Is connected to the input terminal of

In this embodiment, a light emission amount monitoring means 118 for detecting light emission intensity, a DA converter 114 for outputting a signal for stopping light emission, a comparator 115 and an AND gate 117, and a light emitting intensity setting control are provided. The transmitter microcomputer 109 and the DA converter 114 constitute a light emission control unit described in claims.

<Operation of Transmitter> The operation of the transmitter will be described below with reference to the flow chart of FIG. When a power switch (not shown) is turned on, the transmitter microcomputer 109 starts operation (S101), and proceeds to step S102. In step S102, the booster is operated to boost the battery voltage to a higher voltage. After boosting, the charge energy is
03.

Next, in step S103, the setting means 110
Is read by the transmitter microcomputer 109. In step S104, IMAX and the first-byte transmission data D0 are set according to the number of light-emitting lamps read in step S103 from Table 1, and the emission light transmission data (D1 to DIMAX) set in Table 2 is set. Is set. For example, slaves with a maximum of three lights are set, and 1/4, 1
When / 8 and 1/16 light emission is set, IMA
X = 3, D0 = 10000010, and D1 = 10 from Table 2.
000101, D2 = 100000111, D3 = 100
01001.

[0015]

[Table 1]

[0016]

[Table 2]

In the configuration of the transmission data, bit 7 (most significant bit) is a start bit serving as a reference for optical transmission, and is always "1". Transmission is performed in the order of bit 7 to bit 0.

Next, in step S105, the transmitter microcomputer 109 A / D converts the charging voltage of the main capacitor 103 divided by the resistors 107 and 108, and reads the charging voltage (VMC) of the main capacitor.

Next, in step S106, the transmitter microcomputer 109 outputs the data of the light emission intensity to be set to the DA converter 114 from the IMAX set in step S104 according to Table 1. The DA converter 114 outputs a voltage corresponding to the received data to a non-inverting input of the comparator 116.

The data from the microcomputer 109 to the DA converter 114 shown in Table 1 is represented by a hexadecimal number.
The range is from H to FFH. The larger this data is, the more D
The output of the A converter 114 increases. That is, the emission intensity of the optical transmission pulse increases. For example, if you have two lights,
B0 is set in the DA converter 114.

Subsequently, in step S107, it is determined whether or not the charging voltage of the main capacitor 103 is equal to or higher than the luminous charging voltage (VT) (VMC ≧ VT). If VMC ≧ VT, the process proceeds to step S108, where VMC <VT If so, the process proceeds to step S109. In step S109, the open drain port of the transmitter microcomputer 109 is set to High (OPEN) in order to display the light emission prohibition state, the charge completion display LED 111 is turned off, and the process proceeds to step S103. On the other hand, in step S108, the open drain port of the transmitter microcomputer 109 is set to Low to display the light emission permission state, and the charge completion display LED 111 is turned on.

Next, in step S110, it is determined whether or not a light emission start signal is input from a camera (not shown).
If not, the process proceeds to step S103. In step S111, a subroutine for optical communication processing to the slave flash device is called. When the process returns from the subroutine to the main routine in step S111, step S111 is executed.
Go to 103.

<Optical Communication Processing Subroutine> The optical communication transmission subroutine called in step S111 will be described with reference to FIG. When starting in step S201, in step S202, 0 is set to a variable I indicating the number of bytes to be transmitted. next,
In step S203, it is determined whether or not I = 0. If I = 0, the process proceeds to step S204.
Proceed to 205. In step S204, the data D0 of the first byte is set in the transmission buffer of the optical communication.
Proceed to 212.

Next, in step S205, it is determined whether or not I = 1. If I = 1, the process proceeds to step S206, and if not, the process proceeds to step S207. In step S206, the data D1 of the second byte is set in the transmission buffer of the optical communication, and the process proceeds to step S212.

Hereinafter, data DI (0 ≦ I ≦ 4) to be transmitted to the transmission buffer of the optical communication is set up to the maximum number of 5 bytes (IMAX = 4) specified in the optical communication format (step S207). ~ Step S21
1).

Then, in step S212, the optical communication 1
Variable BI indicating the bit number of the byte being processed
Is set to 0, and the 1-byte communication end flag is set to 0.
Further, in step S213, the timer interruption at the communication bit interval is permitted. As a result, the microcomputer 109 receives a timer interrupt at the set interval, and can execute the interrupt process at the set interval.

Next, in step S214, it is determined whether or not the 1-byte communication end flag is 1 in order to determine whether or not the 1-byte optical transmission has been completed.
Proceed to step S15, otherwise proceed to step S214.

Next, in step S215, I ≧ IMA
X, that is, whether the optical communication of the number of bytes set in step S103 has been completed or not, and I ≧ IMAX
If so, the process proceeds to step 217; otherwise, the process proceeds to step S216. In step S216, I = I + 1
In step S203 to transmit the next byte.
Proceed to. On the other hand, in step S217, a light emission start signal for causing each slave flash device to emit light synchronously is transmitted. This signal is used in step S304 of FIG. 4 described below.
The same operation as the one-bit light emission process is performed. Then, in step S218, the optical communication processing ends, and the process returns to the main routine.

<1 Byte Transmission Operation> Next, 1 byte of optical communication
The operation of transmitting bytes will be described with reference to FIGS. 4 and 11A. FIG. 11A shows the waveform of each unit when 1-byte data 10000010 is transmitted.

The timer interrupt is generated by permitting the timer interrupt at a predetermined interval (bit interval of the communication pulse) in step S213 in FIG. The timer interrupt generation timing is the rising edge of the waveform of (A) in FIG.

In step S301, a timer interrupt is started, and in step S302, the transmission buffer is shifted to the left. In step S303, it is determined whether the shifted and pushed bit is 1 or not. If it is 1, the process proceeds to step S304 in which the discharge tube for outputting 1 by light transmission emits light. Otherwise, the process proceeds to step S305 because the discharge tube does not emit light in order to output 0 by light transmission. Step S
In 305, the discharge tube emits light to output 1 by light transmission. In step S304, 1-bit light emission processing described below is performed.

<Step S304: Light Emission Processing of One Bit> First, the output terminal STSP of the microcomputer 109 is set to Hig.
h. At this time, since the discharge tube 105 does not emit light, the output of the light emission amount monitoring means 118 <the DA converter 114
Output. Therefore, the output of the comparator 116 is High.
h, and the inputs of the AND gate 117 are both High, so the output is also High. This is the emission control means 10
The light emission control means 106 forms a discharge loop of the anode 103 of the main capacitor, the discharge tube 105, the light emission control means 106, and the cathode of the main capacitor 103. At this time, the transmitter microcomputer 109 sets the output terminal TRI to the predetermined time Hi.
gh to operate the trigger circuit 104 to excite the discharge tube 105 to start light emission (timing T1 in FIG. 11A). When the light emission intensity of the discharge tube 105 becomes a predetermined value or more, the light emission amount monitoring means Output of 118 ≧ DA converter 114
Therefore, the output of the comparator 116 becomes LOW.
As a result, the output of the AND gate 117 becomes LOW,
The light emission control means 106 interrupts the discharge loop of the anode 103 of the main capacitor, the discharge tube 105, the light emission control means 106, and the cathode of the main capacitor 103. As a result, light emission of 1-bit transmission is stopped (timing of T2 in FIG. 11A).

When the transmitter microcomputer 109 detects LOW after the light emission of the AND gate 117, it sets the STSP terminal to LOW and proceeds to step S305. Step S3
At 05, to determine whether the 1-byte optical communication has been completed, if BI = 7, the process proceeds to step S306; otherwise, the process proceeds to step S307.

In step S306, timer interruption is prohibited, the 1-byte communication end flag is set to 1, and the flow advances to step S309. On the other hand, in step S307,
BI = BI + 1 is performed, and the process proceeds to step S308. In step S308, since the one-byte communication is not completed, the timer interrupt is not prohibited, the one-byte communication end flag is set to 0, and the process proceeds to step S309. Step S30
At 9, the interrupt processing is terminated.

As described above, the transmitter transmits the light emission mode, the light emission amount as light emission of the discharge tube 105, and the non-light emission as 1, 0 digital data to the receiver. The D / A converter 1 according to the number of light-emitting lamps of the receiver set by the setting unit 110
By setting the output of No. 14, the emission intensity of the optical transmission pulse can be changed.

<< Receiver >><Configuration of Receiver> The configuration of the receiver will be described with reference to FIG. In this embodiment, one or more receivers are provided for one transmitter. Reference numeral 501 denotes a battery serving as a power supply; 502, a boosting means for starting boosting the voltage of the battery based on a signal from a microcomputer (hereinafter, referred to as a receiver microcomputer) 507 on the receiver side;
Is a main capacitor for storing the output of the booster. 504
Is a trigger circuit for exciting the discharge tube 505 to emit light, and is connected to the output terminal TRI of the receiver microcomputer 507. Reference numeral 505 denotes a discharge tube for converting electric energy of the main capacitor 503 into light, and 506 denotes a light emission control unit for controlling light emission of the discharge tube 505.

The receiver microcomputer 507 processes each operation of the flash device such as light emission control, light emission amount, and data analysis from the transmitter.

Reference numeral 508 denotes an optical communication light receiving means for receiving optical communication data from the transmitter. 509 is a DA converter,
The DA output is output to the non-inverting input of the comparator 511 according to the data received from DA_OUT of the receiver microcomputer 507. Reference numeral 510 denotes a light emission amount monitoring unit,
And outputs a voltage corresponding to the integration amount to the inverting input of the comparator 511. Reference numeral 511 denotes a comparator, the output of which is output to an AND gate 512. 51
Reference numeral 2 denotes an AND gate. The input terminals other than those connected to the output of the comparator 511 are connected to the STS of the receiver microcomputer 507.
The output is connected to the P terminal, and the output is connected to the light emission control means 506. Reference numeral 513 denotes a slave ID setting unit that indicates the number of the slave of the receiver that is set.

FIG. 13 shows the optical communication light receiving means 50.
8 is shown in detail. In the figure, reference numeral 508_1 denotes a photodiode, a cathode is connected to a power supply, and an anode is connected to a resistor 508_2. The resistance 50
The connection point between 8_2 and the photodiode is the comparator 50
8_5 is connected to the non-inverting input. Resistance 508_3
The resistor 508_4 divides the reference voltage, and the voltage dividing point is connected to the inverting input of the comparator 508_5. The output of the comparator 508_5 is connected to the receiver microcomputer 507 as the output of the optical communication light receiving means 508.

<Operation of Receiver> When a power switch (not shown) on the receiver side is turned on, the receiver microcomputer 50
7 starts the operation of the boosting means 502 and boosts the battery voltage to a high voltage. After the boost, the charge energy is stored in the main capacitor 503.

<Reception of Optical Communication> The operation of the receiver from receiving an optical communication pulse from the transmitter to emitting light will be described with reference to FIGS. 5 and 11B. FIG.
1 (b) shows the waveform of each part when one byte of the optical communication data 10000010 is received. When the optical communication light receiving means 508 receives an optical pulse due to light emission of the transmitter, an interrupt occurs in the receiver microcomputer 507 (FIG. 11).
(Timing of T3 of (b)). The interrupt processing of the optical communication pulse reception will be described with reference to the flow of FIG. In step S401, an interrupt is started, and in step S402
If the light emission permission flag is 1 (that is, if light emission starts)
The process proceeds to step S407, and if 0 (that is, if communication is started), the process proceeds to step S403.

In step S403, 1 is set to a variable RBI indicating the bit of the communication, and the flow advances to step S404. In step S404, the interruption due to the reception of the optical communication pulse is prohibited, and in step S405, the timer microcomputer 507 permits the timer interruption so as to generate the timer interruption at intervals corresponding to the bit interval of the optical communication pulse, and proceeds to step S406. .

In step S406, 1 is set to the least significant bit of the reception buffer, and the flow advances to step S420. In step S420, the interrupt processing ends.

Next, processing at the time of light emission will be described. Step S
In 407, if the slave ID (SID) set by the slave ID setting means 513 is 0, step S408
Otherwise, to step S409. In step S408, in order to set the light emission amount RD1 corresponding to the slave ID = 0 sent from the transmitter by optical communication, the light emission amount RD1 is set in the output buffer to the DA converter.

Hereinafter, from step S409 to S413,
The light emission amount sent from the transmitter corresponding to the slave ID of each receiver is set in the output buffer to the DA converter. In step S414, the output buffer of the D / A converter is used to remove the start bit.
11B and AND. In step S415, it is determined whether the output buffer of the DA converter is 00000000B. If the output buffer is 00000000B, the process proceeds to step S418 to not emit light, and if not, the process proceeds to step S416. In step S416, the output buffer of the DA converter is output to the DA converter 509. In step S417, a light emitting operation is performed. <Light Emitting Operation on Receiver Side> Here, the light emitting operation in step S417 will be described with reference to FIG. In addition,
FIG. 12 shows an optical communication (D0
= 10000000, D1 = 10000011), and shows the light emission start signal and the waveform of each part of the receiver. After the light emission amount corresponding to the slave ID is transmitted from the transmitter by optical communication and the light emission amount is set in the DA converter (after T1 in FIG. 12B), the receiver microcomputer 507 sets the output terminal STSP to High. . As a result, since the discharge tube 505 does not emit light, the output of the light emission amount monitoring means 510 <the output of the DA converter. Therefore, the output of the comparator 511 is High.
h, and the output of the AND gate 512 is also high because both inputs are high. This is the emission control means 506
The light emission control means 506 forms a discharge loop of the anode 503 of the main capacitor, the discharge tube 505, the light emission control means 506, and the cathode of the main capacitor 503. At this time, the receiver microcomputer 509 sets the output terminal TRI to Hig for a predetermined time.
At h, the trigger circuit 504 is operated to excite the discharge tube 505 to start light emission. When the integrated value of the light emission amount of the discharge tube 505 becomes equal to or more than a predetermined value, the output of the light emission amount monitoring means 510 ≧ DA converter 509
Therefore, the output of the comparator 511 becomes Low.
As a result, the output of the AND gate 512 also becomes low (timing of T2 in FIG. 12), and the light emission control means 506 interrupts the discharge loop of the anode 503 of the main capacitor, the discharge tube 505, the light emission control means 506, and the cathode of the main capacitor 503. I do. As a result, light emission stops, and the process proceeds to step S418.

In step S418, received data RD0
Set 0 to RD4. Next, in step S419, the light emission permission flag is set to 0, and the next optical communication interrupt operates at the start of communication, and the process proceeds to step S420.

<Timer Interruption> Next, a timer interrupt process for determining 0 or 1 after the start bit in the optical communication from the transmitter will be described with reference to the flow of FIG. Figure 11 shows the timing of timer interrupt generation.
This is the rise of (M) in (b).

When the process is started in step S501, it is determined in step S502 whether the output of the optical communication light receiving means 508 is "1". If it is 1, the process proceeds to step S504, and if it is 0, the process proceeds to step S503. In step S503, the carry flag is set to 0, and in step S505
Proceed to. In step S504, the carry flag is set to 1, and the process proceeds to step S505.

In step S505, the reception buffer is shifted to the left. At this time, the carry flag is set in the lower-order bit of the reception buffer. Subsequently, step S5
In 06, it is determined whether or not the RBI is 7 in order to determine whether the optical communication has been completed for one byte.
9; otherwise, the process proceeds to step S507. In step S507, RBI = RBI + 1 is performed, and the process proceeds to step S508. When one byte of optical communication is completed,
In step S509, it is determined whether or not the variable RI indicating the byte of the optical communication data is 0. If 0, the process proceeds to step S510; otherwise, the process proceeds to step S512. In step S510, the content of the reception buffer is
The value is set to 0, and the process proceeds to step S511. In step S511, based on the received data RD0, the number of bytes of this communication is determined from the data in Table 1, and RIMAX is set according to the maximum number of bytes.
Proceed to.

On the other hand, in steps 512 to 518, the optical communication data transmitted from the transmitter is set to RD1 to RD4. Then, in step S519, it is determined whether or not RI ≧ RIMAX to determine whether the optical communication has been completed. If RI ≧ RIMAX (optical communication has been completed), the process proceeds to step S520, and RI <RIMAX (during communication). If so, the process proceeds to step S524.

In step S520, RI is set to 0, and the flow advances to step S521. In step S521,
Next, in order to prepare to receive the light pulse of the receiver light emission start signal transmitted by the transmitter, the light emission permission flag is set to 1 and the process proceeds to step S522. On the other hand, step S524
Then, RI = RI + 1 is performed in preparation for receiving the next communication, and the process proceeds to step S522.

In steps S522 and S523, a timer interrupt is disabled and an optical pulse reception interrupt is enabled in order to enable an optical pulse reception interrupt.
Proceed to. In step S508, the timer interrupt ends.

By performing the above-described optical pulse reception interrupt processing and timer interrupt processing, optical communication using an optical pulse sent from the transmitter is enabled, and one or more receivers can control the light emission amount set by the transmitter. It becomes possible to receive. Also, it becomes possible to synchronize the light emission start of each receiver in response to the light emission start signal.

Although the present embodiment has been described with reference to the case where bit 7 (most significant bit) of the 8-bit communication data is used as the start bit, the communication data may have an 8-bit configuration consisting of a start bit + data portion. Often,
Also, a format in which channel bits and stop bits for preventing interference are added may be used. The data communication order may be from bit 0 to bit 7.

Further, in this embodiment, the maximum number of receivers (maximum number of light emitting lamps) is four, but a number other than this number may be used.

(Second Embodiment) Next, a second embodiment of the present invention will be described. Note that the configurations of the transmitter and the receiver in this embodiment are the same as those in the first embodiment.

<Operation of Transmitter> The operation flow of the transmitter is as follows.
The only difference from the operation flow of the first embodiment shown in FIG. 2 is the setting of IMAX, D0 to DIMAX in step S104, and the setting of the DA converter in step S106.

In step S104, IMAX and emission mode transmission data D0 are set according to the number of emission lamps read in step S103 from Table 3 and whether the emission mode is manual emission or multiple emission.

[0059]

[Table 3]

Further, if the light emission mode set in step S103 is the multiple light emission, the light emission frequency is set to D1 from Table 4 and the number of times of light emission is set to D2 from Table 5;
From Table 2, the light emission amount for each slave ID is set in D3 to D6. On the other hand, the flash mode is manual flash (single flash)
If so, the light emission amount for each slave ID is set to D1 to D4 from Table 2.

[0061]

[Table 4]

[0062]

[Table 5]

For example, in the case of two multi-emissions, the emission frequency is 10 Hz, the number of times of emission is 5, and the amount of emission is 1/3 each
If it is 2, 1/64, D0 = 10010001, D1
= 10001010, D3 = 10001011, D4 =
10001101.

In step S106, the set IM
AX outputs data of the light emission intensity to be set to the DA converter 114 according to Table 3. The DA converter 114 outputs a voltage corresponding to the received data to a non-inverting input of the comparator 116.

For example, if the manual light emission is set to three lamps, A0H is output from DA_OUT and 3
If it is set to lamp, 80H is output from DA_OUT. Here, data to the DA converter 114 is represented by a hexadecimal number and has a range from 00H to FFH.
The output of the DA converter 114 increases as the data increases. That is, the light emission intensity of the optical communication pulse increases.

The following transmitter operation is the same as that of the first embodiment. When a light emission start permission signal is input from a camera (not shown), the flow jumps to an optical communication processing subroutine to be described.

<Optical Communication Processing Subroutine> The operation of the optical communication processing subroutine will be described with reference to the flow chart of FIG. In steps S1203 to S1215, D0 to D6 set in step S104 are sequentially set in the optical communication buffer. Steps S1216 to S1218 correspond to steps S212 to 214 shown in FIG. 3 in the first embodiment, and start a timer interrupt for optical communication for one byte of optical communication and confirm the end of one-byte communication. Perform processing. Step S1
Steps 219 to S1222 correspond to steps S215 to S218 of the first embodiment, and perform a process of determining whether all set communication bytes have been completed and a process of emitting a light emission start signal of the receiver.

<Emission Processing of One-Byte Optical Communication> Emission processing of one-byte optical communication is executed according to the same flow as that shown in FIG. 4 in the first embodiment.

<Operation from Optical Input Interruption in Receiver> The operation of the receiver after receiving the start bit in the optical communication from the transmitter will be described with reference to the flow of FIG. The operation from the reception of the start bit to the completion of the optical communication reception is the same as in the first embodiment, and steps S1401 to S1406 in this embodiment correspond to steps S401 to S406 in the first embodiment.

For this reason, the operation of the receiver after receiving the light emission start pulse will be described in accordance with step S1407 and subsequent steps. In step S1407, it is determined from the received data RD0 of the first byte and Table 3 whether the instruction from the transmitter is a multiple light emission mode or a manual light emission mode. If the instruction is a multiple light emission mode, the process proceeds to step S1415. If it is, the process proceeds to step S1408.

First, the operation during manual light emission will be described. In step S1408, it is determined whether or not the slave ID (SID) set by the slave ID setting unit 513 is 0. If it is 0, the process proceeds to step S1409; otherwise, the process proceeds to step S1410. Step S1
In step 409, the light emission amount RD1 sent from the transmitter corresponding to the slave ID = 0 by optical communication is set.
The output buffer to the converter 509 is set. Less than,
Through steps S1410 to S1414, the light emission amount transmitted from the transmitter by optical communication corresponding to the slave ID of each receiver is set in the output buffer to the DA converter 509.

Next, the operation at the time of multiple light emission (step S1)
Steps 415 to S1423) will be described. In step S1415, RD1 is set to a variable multi-F for setting the frequency of multi-light emission. In step S1416, RD2 is set to a variable multi-TS for setting the number of times of multi-light emission. In steps S1417 to S1423, the light emission amount corresponding to the slave ID sent from the transmitter is set.

In step S1424, the output buffer of DA converter 509 is ANDed with 01111111B to remove the start bit. Step S14
25, the output buffer of the DA converter 509 is
It is determined whether it is 000000B or not.
If it is not 000000B, the process proceeds to step S1426.
In step S1426, the output buffer of the DA converter 509 is output to the DA converter 509. In step S1427, a light emitting operation is performed. In step S1428, 0 is set to RD0 to RD6, and the flow advances to step S1429. In step S1429, the light emission permission flag is set to 0, and the next communication interrupt performs a communication operation, and the flow advances to step S1430.

<Light Emitting Operation of Receiver> Next, the light emitting operation of the receiver will be described. The operation of manual light emission is the same as in the first embodiment.

The operation of the multi flash is the same as the manual flash of the first embodiment except that the multi flash set in step S1415 is used.
The multi-light emission is performed by repeating the number of times of the multi-TS set in step S1416 for each frequency interval of.

<Timer Interruption> Next, timer interrupt processing for determining 0 or 1 after the start bit in the optical communication from the transmitter will be described with reference to the flow of FIG. The data receiving method for one byte (from bit 6 to bit 0) from step S1501 to step S1508 is the same as in the first embodiment.

When one byte of optical communication is completed, in step S1509, the RI indicating the number of the byte of the optical communication data is set.
Is determined to be 0, and if it is 0, the process proceeds to step S1510; otherwise, the process proceeds to step S1512. In step S1510, the content of the reception buffer is set to RD0, and the flow advances to step S1511.

In step S1511, based on the received data RD0, the number of bytes of this communication is determined from the data shown in Table 3, RIMAX is set according to the maximum number of bytes, and the flow advances to step S1523.

In steps S1512 to S1522, the optical communication data transmitted from the transmitter is transmitted from RD1 to R
Set to D6.

Steps S1523 to S152
The process of determining whether the optical communication has been completed and the operation of setting the light emission permission flag to 1 after the end of the optical communication are the same as steps S519 to S523 in the first embodiment. In step S1528, RI = RI + 1 is performed in preparation for receiving the next communication. This step S1528 is the first
This corresponds to Step S524 of the embodiment.

As described above, in this embodiment, the light emission mode of the manual light emission and the multiple light emission can be set wirelessly from the transmitter to the receiver, and the receiver can emit light according to the set mode. Further, the light emission amount of the optical communication pulse can be changed depending on the light emission mode and the number of light emitting receivers (the number of light emitting lamps).

(Third Embodiment) Next, a third embodiment of the present invention will be described. The configurations of the transmitter and the receiver in this embodiment are the same as those in the first and second embodiments. The operation flow of the transmitter microcomputer 109 is also shown in FIG.
Other than the setting of the DA converter in step S106
This is the same as the embodiment.

Hereinafter, the DA setting operation in step S106 will be described with reference to FIG. First, step S106_
In 1, 0 is set to QB representing the total number of transmission bits, variable BI representing the bit number, and variable I representing the byte number.

Next, in step S106_2, DI (0 ≦ I ≦ IMAX) is set in the register of the transmitter microcomputer 109. Next, in step S106_3, the register is shifted left. Subsequently, in step S106_4, the register is shifted to the left and the pushed-out bit is 1, if it is 1, the process proceeds to step S106_5, and if it is 0, the process proceeds to step S106.
Go to _6.

In step S106_5, QB = QB +
1 and then the process proceeds to step S106_6. Then, in step S106_6, it is determined whether or not BI = 7 to determine whether the left shift by one byte has been completed. If BI = 7, the process proceeds to step S106_8; otherwise, the process proceeds to step S106_7. In step S106_7, the BI
= BI + 1, and then proceeds to step S106_3.

In step S106_8, in order to determine whether or not all bits of the transmission data have been counted, I <
It is determined whether or not IMAX, and if I <IMAX, the process proceeds to step S106_9. If I ≧ IMAX, the process proceeds to step S106_10. In step S106_9, I
= I + 1, and the process proceeds to step S106_2. On the other hand, in step S106_10, the optical communication total bit Q
The output value to the DA converter 114 corresponding to B is determined.

[0087]

[Table 6]

As described above, it becomes possible to change the charging voltage at which light can be emitted according to the set number of receivers to be controlled (the number of light emitting lamps) and the total number of communication pulse light emission in the light emission mode.

Although the output value to the DA converter 114 is determined for each total communication pulse emission frequency in Table 6, the output value to the DA converter 114 is determined for each total communication pulse emission frequency range as shown in Table 7. May be determined.

[0090]

[Table 7]

(Fourth Embodiment) Next, a fourth embodiment of the present invention will be described. Note that the configurations of the transmitter and the receiver in this embodiment are the same as those in the first embodiment. However, the setting part of DA in step S106 in the operation flow of the transmitter microcomputer 109 is different from that of the first embodiment.

In step S106 of this embodiment, Table 8
, The IMAX set in step S104 and the main capacitor voltage (VM) read in step S105.
In response to (C), the receiver microcomputer 109 outputs data of the emission intensity to be set to the DA converter 114. D
The A converter 114 outputs a voltage corresponding to the received data to a non-inverting input of the comparator 116. For example,
VMC = 310V (300V ≦) with two lights (IMAX = 2)
If VMC <315V), A8H is set in the DA converter 114.

[0093]

[Table 8]

The operation of the receiver is the same as that of the first embodiment except that the operation of the receiver follows Table 8 instead of Table 1.

(Fifth Embodiment) Next, a fifth embodiment of the present invention will be described. Note that the configurations of the transmitter and the receiver in this embodiment are the same as those in the second embodiment. However, the DA setting part of step S106 in the operation flow of the transmitter microcomputer 109 is different from the second embodiment.

In step S106, the light emission mode of manual light emission or multiple light emission set in step S103 according to Table 9, and the IMA set in step S104
X and D from the transmitter microcomputer 109 in accordance with the main capacitor voltage (VMC) read in step S105.
The data of the emission intensity to be set is output to the A converter 114. The DA converter 114 outputs a voltage corresponding to the received data to a non-inverting input of the comparator 116.
For example, multi-emission, two lamps, VMC = 310V (300
If V ≦ VMC <315V), the DA converter 11
4 is set to 88H.

[0097]

[Table 9]

The operation of the receiver is the same as that of the second embodiment except that the operation of the receiver follows Table 9 instead of Table 3.

(Sixth Embodiment) Next, a sixth embodiment of the present invention will be described. Note that the configurations of the transmitter and the receiver in this embodiment are the same as those in the third embodiment. However, the DA setting part of step S106_10 in the operation flow of the transmitter microcomputer 109 is different from the third embodiment.

In step S106_10, a value corresponding to the main capacitor voltage (VMC) and the total optical communication bit QB read in step S105 according to Table 10 is set from the transmitter microcomputer 109 to the DA converter 114.

[0101]

[Table 10]

The operation of the receiver is the same as in the third embodiment.

In Table 10, the output value to the DA converter 114 is determined for each total communication pulse emission frequency.
As shown in FIG. 1, D
The output value to the A converter 114 may be determined.

[0104]

[Table 11]

(Seventh Embodiment) Next, a seventh embodiment of the present invention will be described. In the present embodiment, as shown in FIG.
9 is constituted by a timer for controlling the output time (TP) of the operation signal to the light emission control means 9 and the output terminal (STSP) of the transmitter microcomputer 1109 is directly connected to the light emission control means 1106 in the first embodiment. And different.

Hereinafter, differences in the operation of the transmitter will be described with reference to the flowchart of FIG. The difference from the first embodiment is that in step S1104, IMAX and transmission data D0 are set according to the number of light-emitting lamps read in step S1103 from table 12, and the light emission amount transmission data ( D1 to DIMAX) are set.

[0107]

[Table 12]

Then, instead of setting the DA in step S106, in step S1106 step S110
The TP for emitting one communication pulse corresponding to the IMAX set in 4 is set from Table 12.

The other operations of the transmitter are almost the same as those of the first embodiment, but are different in the operation of the one-bit light emission process in step S304 in FIG. Hereinafter, the operation of the one-bit light emission process will be described with reference to the flow of FIG.

<Step S304: Light Emitting Process of One Bit> When starting in step S2001, step S304 starts.
In 2002, the output terminal STSP of the transmitter microcomputer 1109
To High. This is input to the light emission control means 106, and the light emission control means 1106
3. A discharge loop of the discharge tube 1105, the light emission control means 1106, and the cathode of the main capacitor 1103 is formed.

Next, in step S2003, the transmitter microcomputer 1109 sets the output terminal TRI to High to operate the trigger circuit 1104 to excite the discharge tube 1105 to start light emission. At the same time, a 1-bit light emission time timer of the transmitter microcomputer 1109 is started in step S2004.

In step S2005, it is determined whether the timer of the 1-bit optical communication of the transmitter microcomputer 1109 ≧ TP. If so, the process proceeds to step S2006. Otherwise, the determination is made until the timer ≧ TP. repeat.

In step S2006, by setting the output terminal STSP of the transmitter microcomputer 1109 to Low, the light emission control means 1106 controls the anode 1103 of the main capacitor,
The discharge loop of the discharge tube 1105, the emission control means 1106, and the cathode of the main capacitor 1103 is cut off. This gives 1
The light emission of the bit transmission stops.

In step S2007, the transmitter microcomputer 1109 sets the output terminal TRI to low, and in step S2
Proceed to 008. Then, in step S2008, the 1-bit light emission process ends, and the process proceeds to step S305 in FIG.

The operation of the receiver is the same as in the first embodiment.

As described above, optical communication can be performed from the transmitter to the receiver. The light emission amount control means outputs the operation signal (T) to the light emission control means of the transmitter microcomputer 1109 in FIG.
Since it is configured with a timer for controlling P), a circuit can be configured at a lower cost than that of the first embodiment.

[0117]

As described above, according to the present invention, the flash emission amount of the transmitter is reduced when the transmission amount is large or when the charging voltage of the flash emission capacitor is low. Energy required for transmission can be reduced, and light emission loss (transmission leakage) due to excessively low capacitor voltage during transmission can be prevented. In addition, even when the transmission amount is large, it is not necessary to unnecessarily increase the luminous voltage of the capacitor, and the capacitor charging time up to the luminous voltage can be shortened. Therefore, it is possible to shorten the charge waiting time even during continuous light emission. Further, the optimum transmitter-side light emission amount can be determined from the transmission amount and the capacitor charging voltage.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a transmitter and a receiver constituting a flash control system according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing an operation of the transmitter.

FIG. 3 is a flowchart showing an optical communication operation of the transmitter.

FIG. 4 is a flowchart showing a 1-byte optical communication operation of the transmitter.

FIG. 5 is a flowchart showing the operation of the receiver.

FIG. 6 is a flowchart illustrating an optical communication receiving operation of the receiver.

FIG. 7 is a flowchart illustrating an optical communication operation of a transmitter according to a second embodiment of the present invention.

FIG. 8 is a flowchart illustrating an operation of the receiver according to the second embodiment.

FIG. 9 is a flowchart illustrating an optical communication receiving operation of the receiver according to the second embodiment.

FIG. 10 is a flowchart illustrating a DA_OUT setting operation of a transmitter constituting a flash control system according to a third embodiment of the present invention.

FIG. 11 is a diagram illustrating waveforms of respective units of the transmitter and the receiver according to the first to third embodiments during 1-byte communication.

FIG. 12 is a diagram illustrating waveforms of respective units from reception of communication of the receiver of the first to third embodiments to emission of light.

FIG. 13 is a detailed diagram of a configuration of an optical communication receiving unit of the receiver according to the first to third embodiments.

FIG. 14 is a diagram illustrating a configuration of a transmitter constituting a flash control system according to a seventh embodiment of the present invention.

FIG. 15 is a flowchart illustrating an operation of the transmitter according to the seventh embodiment.

FIG. 16 is a flowchart illustrating a 1-bit light emission operation of the transmitter according to the seventh embodiment.

[Explanation of symbols]

 103, 503, 1103 Main capacitor 105, 505, 1105 Discharge tube 111, 1111 Charge completion display LED 116, 511 Comparator

Claims (22)

[Claims] 1. An optical transmission device for transmitting information using light emission of a flash light emitting means, comprising: a light emission control means for controlling a light emission amount of the flash light emitting means in accordance with an amount of information to be transmitted. Optical transmitter. 2. The optical transmission device according to claim 1, wherein the light emission control means controls light emission intensity of the flash light emission means. 3. The optical transmission device according to claim 1, wherein the light emission control means controls a light emission time of the flash light emission means. 4. The total number of light emission of the flash light emitting means differs according to the amount of information to be transmitted, and the light emission control means controls the amount of light emission of the flash light emitting means according to the total number of light emission. Claim 1
4. The optical transmission device according to any one of items 1 to 3. 5. An optical transmitter comprising: the optical transmitter according to claim 1; and a slave flash device that emits a flash according to information transmitted from the optical transmitter. Features a flash control system. 6. The optical transmission device can control one or a plurality of slave flash devices, and the amount of information transmitted from the optical transmission device varies according to the number of slave flash devices to emit light. The flash control system according to claim 5. 7. The flash control system according to claim 6, wherein the information transmitted from the optical transmission device includes an instruction value of a light emission amount of each of the slave flash devices. 8. The amount of information transmitted from the optical transmitter is:
6. The flash control system according to claim 5, wherein said flash control system differs depending on a light emission mode of said slave flash device. 9. The information transmitted from the optical transmission device includes an instruction value of an emission frequency, an emission frequency, and an emission amount of the slave flash device in a multi-emission mode, and an emission value of the slave flash device in a single emission mode. 9. The flash control system of claim 8, including an indication of the amount. 10. An optical transmitter for transmitting information by using light emission of a transmission flash light emitting unit that emits light using electric energy charged in a capacitor, comprising: a detecting unit that detects a state of charge of the capacitor; An optical transmission device comprising: a light emission control unit that controls a light emission amount of the flash light emission unit according to a charged state detected by the detection unit. 11. The optical transmission device according to claim 10, wherein said light emission control means controls light emission intensity of said flash light emission means. 12. The optical transmission device according to claim 10, wherein the light emission control means controls a light emission time of the flash light emission means. 13. An optical transmitter comprising: the optical transmitter according to claim 10; and a slave flash device that emits a flash according to information transmitted from the optical transmitter. Features a flash control system. 14. An optical transmitting apparatus for transmitting information by using light emission of a flash light emitting means that emits light using electric energy charged in a capacitor, a detecting means for detecting a charged state of the capacitor, and the detecting means A light emission control means for controlling a light emission amount of the flash light emission means in accordance with a state of charge detected by the device and an amount of information to be transmitted. 15. The optical transmission device according to claim 14, wherein said light emission control means controls light emission intensity of said flash light emission means. 16. The optical transmitter according to claim 14, wherein the light emission control means controls a light emission time of the flash light emission means. 17. The total number of times of flash light emission of the flash light emitting means differs according to the amount of information to be transmitted, and the light emission control means controls the flash light emission according to the state of charge detected by the detection means and the total number of light emissions. 15. The method according to claim 14, wherein the light emission amount of the means is controlled.
7. The optical transmission device according to any one of 6. 18. An optical transmitter comprising: the optical transmitter according to claim 14; and a slave flash device that emits a flash according to information transmitted from the optical transmitter. Features a flash control system. 19. The optical transmission device is capable of controlling one or a plurality of slave flash devices, and the amount of information transmitted from the optical transmission device varies according to the number of slave flash devices to emit light. The flash control system according to claim 18. 20. The information transmitted from the optical transmission device,
19. The flash control system according to claim 18, further comprising an instruction value of a light emission amount of each of the slave flash devices. 21. The flash control system according to claim 18, wherein the amount of information transmitted from said optical transmission device differs according to a light emission mode of said slave flash device. 22. The information transmitted from the optical transmission device,
22. The multi-emission mode includes an emission frequency, a number of times of emission, and an emission amount of the slave flash device, and the single emission mode includes an emission amount of the slave flash device. The flash control system as described.