JP5590792B2 - Illumination device, imaging device, and charging control method - Google Patents

Description

The present invention relates to lighting equipment, an imaging device and a charging control method having a plurality of light emitting portions.

2. Description of the Related Art A lighting device having a plurality of light emitting means is known as a lighting device used at the time of flash photography with an imaging device typified by a digital camera. For example, Patent Document 1 discloses a flash light emitting device having a first light emitting means made of a xenon tube and a second light emitting means made of a light emitting diode (hereinafter referred to as LED) as a plurality of light emitting means.
Japanese Patent Laid-Open No. 10-206942

  In Cited Document 1, since there is a light emitting unit that differs greatly in voltage and current required for flash emission, such as a xenon tube and an LED, a capacitor for supplying electric power necessary for flash emission is provided for each light emitting unit. I have.

  However, when performing strobe photography using a lighting device having a configuration including a plurality of light emitting means and a capacitor corresponding thereto, when the capacitor corresponding to the light emitting means to be used has been discharged, There are the following problems.

  That is, in the above case, it is necessary to charge the capacitor corresponding to the light emitting unit to be used by boosting the battery voltage again in order to re-emit the light emitting means that has been discharged by the corresponding capacitor, and it takes time until flash photography. There is a problem that it takes.

An object of the present invention, the shortening of the charging time of the capacitor, lighting equipment capable of achieving effective utilization of energy stored in the capacitor of the light-emitting portion for driving is not used in flash photography, an imaging device and a charging control method Is to provide.

In order to achieve the above object, a lighting device according to the present invention emits light from a first light emitting means, a second light emitting means having a voltage required for light emission different from that of the first light emitting means, and the first light emitting means. A first capacitor used for causing the second light emitting means to emit light, and a first capacitor for converting the voltage of the first capacitor to charge the second capacitor. control and the second control in which the second converts the voltage of the capacitor to charge said first capacitor, and a voltage converting means which is capable, the charge control of said first capacitor and said second capacitor Charging control means for performing the switching, wherein the charging control means switches between the first capacitor and the second capacitor to be charged by the voltage conversion means .

In addition, an imaging apparatus according to the present invention includes the illumination device .

According to the onset bright, it is possible as well as shorten the time of charging the capacitor to a chromatic Kori the energy charged in the capacitor of the light-emitting portion for driving is not used in flash photography.

  Hereinafter, the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a block diagram of a lighting device according to an embodiment of the present invention.

  In FIG. 1, a light emitting device includes a battery 1 serving as an input power source, a capacitor 4 for driving a xenon (Xe) tube and a voltage conversion circuit 2 for charging a capacitor 6 for driving an LED, a capacitor 4 (first capacitor), and A capacitor 6 (second capacitor) is provided.

  The lighting device includes a xenon tube 5, an LED (light emitting diode) 7, a trigger circuit 8 that drives the xenon tube 5, a drive circuit 9 that emits light from the LED 7, a trigger circuit 8, and a CPU 10 that controls the drive circuit 9.

  The voltage conversion circuit 2 includes a voltage conversion transformer 20, a switch circuit 3 including switches 31, 32, 33, 34, and 35 for switching the configuration of the charging circuit, and choke coils 14 and 15.

  The voltage conversion circuit 2 converts the input voltage according to a control signal from the CPU 10 and charges the capacitor 4 or the capacitor 6. The transformer 20 of the voltage conversion circuit 2 is commonly used for charging the capacitor 4 for driving the xenon tube and charging the capacitor 6 for driving the LED.

  The switches 31 to 35 included in the voltage conversion circuit 2 are turned on / off or repeatedly turned on / off by control signals (switch switching signals) 111, 112, 113, 114, 115 from the CPU 10 in accordance with the voltage conversion state. Switch to operation. This has a function of switching the configuration of the voltage conversion circuit 2. In practice, it is configured using transistors, FETs, and the like.

  The charging voltage detection circuit 30 detects the charging voltage of the capacitor 4 and the capacitor 6.

  The functions of the xenon tube 5, the trigger circuit 8, the LED 7, the drive circuit 9, and the choke coils 14 and 15 in FIG. 1 can be realized by adopting a general device suitable for the use of the lighting device.

  Here, the xenon tube 5 and the LED 7 function as a first light emitting unit and a second light emitting unit, respectively, as a light source for flash photography. The transformer 20 and the switches 31 to 35 function as charging means that charges the plurality of capacitors 4 and 6 by boosting the battery voltage.

  Further, the CPU 10 functions as a charging control unit that controls charging of a plurality of capacitors by controlling the charging unit and the voltage conversion unit. Then, the CPU 10 as the charge control means charges the capacitor of the light emitting means suitable for the photographing condition from the battery 1 or the other capacitor among the first and second light emitting means.

  2 (FIGS. 2A and 2B) is a timing chart showing the voltage conversion operations of the voltage conversion circuit 2 in FIG. 1 and the control states of the switches 31-35.

  3 (FIGS. 3A and 3B) is a block diagram showing the operation of the voltage conversion circuit 2 when the voltage of the battery 1 in FIG. 1 is converted and the capacitor 4 is charged.

  4 (FIGS. 4A and 4B) is a block diagram showing the operation of the voltage conversion circuit 2 when the voltage of the capacitor 4 in FIG. 1 is converted and the capacitor 6 is charged.

  Hereinafter, the state of the switches 31 to 35 and the operation of the voltage conversion circuit 2 will be described with reference to FIGS. 2, 3 and 4.

  When the charging operation from the battery 1 to the capacitor 4 is performed, the switches 31 to 35 are controlled by a control signal from the CPU 10 as shown in FIG.

  In FIG. 3A, the switch 31 is turned on by the control signal 111. At this time, energy is stored in the transformer 20 by flowing the battery input current 16 from the battery 1 through the primary winding of the transformer 20.

  In FIG. 3B, the switch 31 is turned off by the control signal 111, and at the same time, the switch 32 is turned on by the control signal 112. At this time, the energy stored in the transformer 20 is charged into the capacitor 4. The switches 33, 34, and 35 are fixed off.

  As a result, the voltage conversion circuit 2 forms a flyback circuit that sends the energy stored in the transformer 20 from the battery 1 to the capacitor 4 and performs charging.

  When the charging operation from the battery 1 to the capacitor 6 is performed, each switch is controlled by a control signal from the CPU 10 as shown in FIG. 2A (b). The basic operation is the same as that for charging the capacitor 4 by converting the voltage of the battery 1. The capacitor 6 is charged by switching the switch 34 by the control signal 114 instead of the switch 32.

  When the charging operation from the capacitor 4 to the capacitor 6 is performed, each switch is controlled by a control signal from the CPU 10 as shown in FIG.

  In FIG. 4A, the switches 32 and 34 are turned on by the control signals 112 and 114, respectively. Due to the discharge current 18 of the capacitor 4 flowing when the energy charged in the capacitor 4 by the switch 32 is discharged through the transformer 20, an induced current is generated in the winding to which the switch 34 of the transformer 20 is connected. This becomes the charging current 19 of the capacitor 6 to charge the capacitor 6.

  Further, as shown in FIG. 4B, the switch 35 is turned on by the control signal 115 and controlled to hold the charging current 19 of the capacitor 6 during the period when the switches 32 and 34 are turned off. The switch 33 is fixed to OFF. As a result, the voltage conversion circuit 2 constitutes a forward circuit.

  When performing the charging operation from the capacitor 6 to the capacitor 4, each switch is controlled by a control signal from the CPU 10, as shown in FIG. 2D (d). The basic operation is the same as that when the voltage of the capacitor 4 is converted to charge the capacitor 6, and the switch 33 is switched by the control signal 113 instead of the switch 35.

  FIG. 5 is a flowchart showing the procedure of the strobe photographing process executed by the illumination device of FIG.

  This process is executed under the control of the CPU 10 in FIG.

  Hereinafter, the operation of flash photography will be described with reference to FIGS.

  When shooting is instructed, the CPU 10 determines which of the xenon tube 5 and the LED 7 is used for flash photography (S10). The light emitting means to be used at the time of flash photography may be determined in advance by the photographer from the menu screen, or may be automatically determined according to the photographing conditions and photographing mode at the time of photographing. For example, as shooting conditions at the time of shooting, the xenon tube 5 that can emit light with a large amount of light emission is used when the distance of the subject is far, and the LED 7 is used when the distance of the subject is short. When it is determined that the xenon tube 5 is used, the CPU 10 detects the charged state of the xenon tube light emitting capacitor 4 by the charge voltage detection circuit 30 (S20).

  If the charging of the capacitor 4 has been completed, the CPU 10 sends a light emission signal 12 to the trigger circuit 8 to cause the xenon tube 5 to emit light and perform photographing (S21).

  On the other hand, when the capacitor 4 is not charged, the CPU 10 uses the charging voltage detection circuit 30 to detect the charging state of the LED light emitting capacitor 6 (S40). In the present embodiment, the charging state of the capacitor 4 and the capacitor 6 is detected by the same charging voltage detection circuit. However, different charging voltage detection circuits may be provided to detect the charging state.

  When the capacitor 6 is charged, the CPU 10 performs a switch switching process for charging the capacitor 4 from the capacitor 6 (S41), and executes charging from the capacitor 6 to the capacitor 4 (S42).

  As a result, when the charging of the capacitor 4 is completed, the CPU 10 causes the xenon tube 5 to emit light and performs photographing (S21).

  If the charging of the capacitor 6 is not completed in S40, the CPU 10 performs a switch switching process for converting the voltage of the battery 1 to charge the capacitor 4 (S43), and charges the capacitor 4 (S44). ). Then, after completing the charging, the CPU 10 causes the xenon tube 5 to emit light and performs photographing (S21).

  When it is determined in S10 that the LED 7 is used, the CPU 10 detects the charge state of the LED light emitting capacitor 6 by the charge voltage detection circuit 30 (S30).

  If the charging of the capacitor 6 has been completed, the CPU 10 sends a light emission signal 13 to the drive circuit 9 to cause the LED 7 to emit light and perform photographing (S31).

  When the charging of the capacitor 6 is not completed, the CPU 10 detects the charged state of the capacitor 4 for xenon tube light emission by the charging voltage detection circuit 30 (S50).

  And when the capacitor | condenser 4 is charged, CPU10 performs the switch switching process for charging the capacitor | condenser 6 from the capacitor | condenser 4 (S51), and performs the charge from the capacitor | condenser 4 to the capacitor | condenser 6 (S52).

  As a result, when the charging of the capacitor 6 is completed, the CPU 10 causes the LED 7 to emit light and performs photographing (S31).

  If the capacitor 4 is not charged in S50, the CPU 10 performs a switch switching process for converting the voltage of the battery 1 to charge the capacitor 6 (S53), and charges the capacitor 6 (S54). Then, after completing the charging, the CPU 10 causes the LED 7 to emit light and perform photographing (S31).

  Here, the voltage charged in the capacitor 4 corresponding to the xenon tube 5 is higher than the voltage charged in the capacitor 6 corresponding to the LED 7.

  In the present embodiment, when charging a capacitor corresponding to the light emission means used for flash photography, it is possible to charge using either the battery 1 or a capacitor corresponding to the light emission means not used for flash photography. In terms of circuit configuration, conversion of the charge between the capacitor 4 and the capacitor 6 is performed by a forward voltage conversion circuit.

  Therefore, compared with the case where charging is performed by directly converting the voltage from the battery 1, the charging time is shortened and the photographing interval can be shortened. In addition, the energy charged in the capacitor corresponding to the light emitting means that is not used for flash photography can be used effectively. Furthermore, since the load current required for charging the capacitor is not directly applied to the battery 1 at this time, it is not necessary to take measures such as limiting the charging current at the expense of charging time.

  In the present embodiment, only the configuration of the strobe device has been described. However, the configuration of the present embodiment is not limited to the external strobe mounted on the imaging device, and has a plurality of light emitting means and each has an individual capacitor. You may apply to an imaging device.

  In the present embodiment, the plurality of light emitting units are configured to include a xenon tube and an LED. However, if the light emitting unit has different voltages required for light emission, the xenon tube and the LED may not be used.

It is a block diagram of the illuminating device which concerns on embodiment of this invention. 6 is a timing chart (1) illustrating each voltage conversion operation of the voltage conversion circuit 2 in FIG. 1 and the control state of switches 31 to 35. 6 is a timing chart (2) illustrating each voltage conversion operation of the voltage conversion circuit 2 in FIG. 1 and the control state of switches 31 to 35. It is a block diagram showing operation | movement of the voltage conversion circuit 2 at the time of converting the voltage of the battery 1 in FIG. 1, and charging the 1st capacitor | condenser 4 (1). It is a block diagram showing the operation | movement of the voltage conversion circuit 2 at the time of converting the voltage of the battery 1 in FIG. 1, and charging the 1st capacitor | condenser 4 (2). It is a block diagram showing the operation | movement of the voltage conversion circuit 2 at the time of converting the voltage of the 1st capacitor | condenser 4 in FIG. 1, and charging the 2nd capacitor | condenser (1). It is a block diagram showing the operation | movement of the voltage conversion circuit 2 at the time of converting the voltage of the 1st capacitor | condenser 4 in FIG. 1, and charging the 2nd capacitor | condenser 6 (2). It is a flowchart which shows the procedure of the flash imaging | photography process performed by the illuminating device of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Battery 2 Voltage conversion circuit 3 Switch circuit 4 Capacitor 5 Xenon tube 6 Capacitor 7 Light emitting diode (LED)
8 Trigger circuit 9 Drive circuit 10 CPU
20 transformer 30 charge voltage detection circuit 31, 32, 33, 34, 35 switch

Claims (5)

First light emitting means;
A second light emitting means having a voltage required for light emission different from that of the first light emitting means;
A first capacitor used when causing the first light emitting means to emit light;
A second capacitor used when the second light emitting means emits light;
A first control for converting the voltage of the first capacitor to charge the second capacitor; a second control for converting the voltage of the second capacitor to charge the first capacitor; Voltage conversion means capable of
And a charging control means for charging control of the first capacitor and the second capacitor,
The illuminating apparatus characterized in that the charge control means switches which of the first capacitor and the second capacitor is charged by the voltage conversion means . The charge control unit, of the first light emitting unit and the second light emitting means is used when making the light emitting means suitable for shooting conditions when shooting by the illumination device to emit light imaging device The lighting device according to claim 1, wherein the capacitor is controlled to be charged from the other capacitor.   3. The illumination device according to claim 1, wherein one of the first light emitting unit and the second light emitting unit is a light emitting diode, and the other is a xenon tube. The imaging device which has an illuminating device of any one of Claims 1 thru | or 3. A first light emitting unit; a second light emitting unit having a voltage required for light emission different from that of the first light emitting unit; a first capacitor used when the first light emitting unit emits light; and the second light emitting unit. A charge control method for a lighting device comprising: a second capacitor used to emit light;
A first control for converting the voltage of the first capacitor to charge the second capacitor and a second control for converting the voltage of the second capacitor to charge the first capacitor are possible. and a voltage conversion step such,
Charging control method of a lighting device characterized by obtaining Bei and a charge control step of switching whether to charge by the voltage conversion step which of said first capacitor and said second capacitor.

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