JP2000221570A - Still video camera and stroboscopic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a more natural photographed image by making the color temperature of strobe light suitable to the color temperature of peripheral light and controlling the emitted light quantity. SOLUTION: When an IGBT 52 is turned on, the charge of a trigger capacitor C1 of a trigger circuit 54 connected to the trigger electrode of a xenon bulb 41 is discharged, then, the light starts to be emitted from the xenon bulb 41. When an IGBT 53 is turned on, the charge of a trigger capacitor C2 of a trigger circuit 55 connected to the trigger electrode of a xenon bulb 45 is discharged, then, the light starts to be emitted from the xenon bulb 45. The color temperature of the emitted light from the xenon bulbs 41 and 45 is converted to another color temperature by filters 40 and 44. Then, by controlling the emitted light quantities of the respective xenon bulbs 41 and 45 by a strobe light control circuit and a timer circuit, the color temperature of the emitted light of the whole stroboscopic device is made to comform to the color temperature of the peripheral light of the object.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a strobe device and a still video camera for performing white balance control during flash photography.

[0002]

2. Description of the Related Art In a conventional still video camera, a white balance is adjusted so that a white subject is photographed white regardless of the color temperature of illumination light. For example, in a still video camera equipped with a strobe device, the white balance adjustment when the strobe is fired is performed by adjusting each color signal so that a captured image obtained when the entire subject is irradiated at the color temperature of the strobe light becomes more natural. Is performed.

[0003] The color temperature of light emitted from a xenon tube used for an arc tube of a strobe device is relatively higher than that of a general electric lamp such as a fluorescent lamp. For this reason, white balance adjustment at the time of flash emission is controlled so that blue is suppressed in the entire image in order to prevent a white subject from being reproduced with a blue color due to the flash light.

However, when illumination light having a color temperature different from that of strobe light is present in a subject, an unnatural color may be reproduced in an image photographed by such control.
For example, as shown in FIG. 56A, when an incandescent lamp LT such as a tungsten lamp is lit above a person M standing in front of a wall W, the color temperature of the illumination light of the incandescent lamp LT Is lower than the illumination light from the strobe device ST, the color of the image of the human M is appropriately reproduced in the captured image as shown in FIG. The color of W is shifted to the red side.

As a device for preventing such an unnatural color from being reproduced, white balance adjustment at the time of light emission of the strobe device is performed by adjusting the color temperature of the strobe light, the color temperature of the external light, or the strobe light and the external light. There is conventionally known a configuration in which any one of intermediate color temperatures is automatically selected and white balance adjustment is performed according to the color temperature.

[0006]

However, in such a conventional configuration, the white balance adjustment faithful to the respective conditions is not performed between the portion where the strobe light is irradiated and the portion where the strobe light is not irradiated. It is difficult to realize more natural color reproduction over the entire shooting screen.

SUMMARY OF THE INVENTION In view of the above problems, the present invention provides a strobe device for improving the color reproducibility of a photographed screen obtained by still photography with strobe light emission, and a still video camera equipped with the strobe device. It is intended to provide.

[0008]

Embodiments of the present invention will be described below. FIG. 1 is a block circuit diagram of a still video camera equipped with a strobe device 25 according to a first embodiment of the present invention.
In this figure, a system control circuit 22 for controlling each circuit includes an image pickup device driving circuit 26, a strobe light control circuit 29, a strobe charging / emitting circuit 58, a filter control circuit 63, a colorimetric circuit 24, an exposure operation circuit 32, The aperture drive circuit 27, the D / A converters 86 and 88, and the release switch 33 are connected.

A solid-state image pickup device (CCD) 11 having an electronic shutter function is connected to the image pickup device drive circuit 26, and an image of a subject 35 incident through the image pickup optical system lens 36 and the diaphragm 20 is transferred to the CCD 11 Is converted into an electric signal. An aperture 20 is connected to the aperture drive circuit 27, and the amount of light incident on the CCD 11 is adjusted.
The CCD 11 has a signal processing circuit 15 and an amplifier 8.
4 and 87 are connected, and the converted color signals are output to these circuits 15, 84 and 87.

A recording circuit 19 is connected to the signal processing circuit 15 so that a video signal which has been subjected to predetermined signal processing is
The data is input to the recording circuit 19. The recording circuit 19 is equipped with a magnetic disk (not shown), and video signals are recorded on each track of the magnetic disk in a color-difference line-sequential manner.

The xenon tube 41 is connected to the strobe charging / light emitting circuit 58, and controls strobe light emission and charge control for light emission.

A color temperature conversion filter 67 connected to a filter control circuit 63 is provided in front of the xenon tube 41, and the color temperature of light emitted from the xenon tube 41 is adjusted by the filter 67. Although the structure of the color temperature conversion filter 67 will be described later, the transparent electrodes 78a, 78
b (FIG. 6) a guest-host (GH) liquid crystal cell is used. The color temperature of the light F2 transmitted through the color temperature conversion filter 67 is determined by the filter control circuit 63 from the transparent electrode 7.
It is adjusted by the amplitude value of the voltage applied to 8a, 78b.

The flash light control circuit 29 includes a photometric sensor 28
Is connected, and the strobe light control circuit 29 measures the amount of strobe light emitted from the xenon tube 41 and reflected by the subject 35, and stops the light emission of the xenon tube 41 when the target light amount is reached. An optical signal (quench signal) S6 is output to the strobe charging / light emitting circuit 58.

The colorimetric circuit 24 is connected to a colorimetric sensor 23 composed of a plurality of photoelectric conversion elements and the like each having a filter having a different spectral distribution of transmitted light. The white balance is measured, and the color measurement result is used as a white balance control factor.

The measurement of the color temperature of ambient light by the colorimetric sensor 23 will be described. The ratio (R / G or B / G) of the output signals of the photoelectric conversion elements having different spectral sensitivities corresponds one-to-one to the color temperature of the received light. Therefore, the output signal ratio (R /
G or B / G), the color temperature of the ambient light F4 is determined. The colorimetric circuit 24 stores a data table indicating a correspondence between a signal value (R / G or B / G) input from the colorimetric sensor 23 and color temperature information in the signal value. Using this data table, the color temperature of the ambient light F4 is determined from the signal value input from the colorimetric sensor 23.

A photometry circuit 31 is connected to the exposure calculation circuit 32, and a photometry sensor 30 including a photoelectric conversion element is connected to the photometry circuit 31. Photometric sensor 30, photometric circuit 3
By 1, the brightness of the subject 35 is measured, and the exposure calculation circuit 32 performs an exposure calculation from the photometric value.

The release switch 33 is a button switch having two open / close contacts. As will be described later, the system control circuit 22 controls the photometry, the color measurement, the opening of the aperture 20, the electronic shutter, and the like. Command.

The colorimetric sensor 23 and the colorimetric circuit 24 are colorimetric means, the color temperature conversion filter 67 and the filter control circuit 63 are color temperature variable means, and the amplifiers 84 and 87 and the D / A converters 86 and 88 are colorimetric. The signal control means, the photometric sensor 28 and the flash dimming circuit 29 constitute a flash dimming means, and the photometric sensor 30, the photometric circuit 31 and the exposure calculating circuit 32 constitute a photometric means. Note that another flash tube may be used for the xenon tube 41 as the strobe light emitting means.

The white balance will be described briefly. The proportions of the R component and the B component in white change with the color temperature, and the G component also changes with the color temperature. However, the R component, the B component, and the G component change with brightness even at the same color temperature. On the other hand, R / G signal and B / G
The signal is not affected by the brightness, and a value corresponding to the color temperature on a one-to-one basis is obtained (FIG. 2). Therefore, the ratio between the R signal / G signal and the B signal / G signal is obtained, and the gains of the color signals R and B are adjusted based on the ratio, that is, the color temperature.

FIG. 3 is a circuit diagram of the flash dimming circuit 29. In this figure, the opposite-phase input terminal 6 of the operational amplifier 60 is shown.
An integrating capacitor 64 and a switch 66 are connected in parallel between 0a and the output terminal 60c, and a photometric sensor 28, which is a photoelectric conversion element such as a photodiode, is connected between the negative-phase input terminal 60a and the positive-phase input terminal 60b. . The reference voltage power supply 68 is connected to the positive-phase input terminal 60b, and the operational amplifier 60 integrates the photocurrent of the photometric sensor 28 that changes due to the reflected light from the subject 35.

The integration of the operational amplifier 60 is started when the contact of the reset switch 66 is opened by the integration start signal S5 input from the system control circuit 22. The output terminal 60c of the operational amplifier 60 is connected to the negative-phase input terminal of the comparator 61. The output terminal of the D / A converter 62 is connected to the positive-phase input terminal of the comparator 61. The D / A converter 62 has a proper integration value S9 as dimming level setting data for controlling the light emission time of the xenon tube 41 from the system control circuit 22.
Is entered. The output terminal of the comparator 61 is connected to the system control circuit 22, and the appropriate integral value S
9 is compared with the output voltage value of the operational amplifier 60, and the quench signal S6 is output.

FIG. 4 is a circuit diagram of the entire strobe device 25 according to the first embodiment having a strobe charging / light emitting circuit 58 and a xenon tube 41. In this figure, two output terminals of the charging circuit 50 are connected to a main capacitor C5, a thyristor 136, a neon tube 132 connected in series with a resistor R14, and a thyristor 124 connected to a resistor R15.
In addition, the xenon tubes 41 are connected in parallel. Charging circuit 50
Is connected to the system control circuit 22, and receives a charge start signal S2. The thyristor 136 is provided between the gate terminal and the cathode terminal of the thyristor 136.
A resistor R16 and a capacitor C6 are connected in parallel in order to prevent the erroneous operation due to leakage current. This gate terminal is connected to the output terminal of the comparator 61 so that the above-mentioned quench signal S6 is input via the input protection resistor R17.

The connection point between the resistor R14 and the neon tube 132 is connected to the system control circuit 22 and outputs a charge completion signal S23. Thyristor 124
A capacitor C8 and a resistor R18 are connected in parallel so that the thyristor 124 does not malfunction due to leakage current. The gate terminal of the thyristor 124 is connected to the system control circuit 22 via the resistor R19, and receives the light emission trigger signal S24.

The anode terminal of the thyristor 124 is connected to the resistor R15 and one end of the capacitor C7. The other end of the capacitor C7 is connected to the low voltage side coil of the trigger transformer T3. The high voltage side coil of the trigger transformer T3 is connected to the trigger electrode of the xenon tube 41. A color temperature conversion filter 67 connected to a filter control circuit 63 is provided on the front surface of the xenon tube 41, and the color temperature of light emitted from the xenon tube 41 is adjusted by the color temperature conversion filter 67. Although the structure of the color temperature conversion filter 67 will be described later, the transparent electrodes 78a and 78b
A guest-host (GH) liquid crystal cell having (FIG. 6) is used. The transparent electrodes 78a and 78b are connected to the filter control circuit 63, and receive rectangular wave signals 216 and 218 having opposite polarities or in-phase. The color temperature of the light F2 transmitted through the color temperature conversion filter 67 is adjusted by the amplitude value of the voltage applied to the transparent electrodes 78a and 78b from the filter control circuit 63.

FIG. 5 is a circuit diagram of the filter control circuit 63. The oscillation circuit 150 includes three inverters 150a to
150c, two resistors 150d and 150e, and a capacitor 150f. The output terminal of the oscillation circuit 150 is connected to the input terminals of the inverter buffer 168 and the non-inverter buffer 170 and the base terminal of the transistor 164 via the resistor 166. Inverter buffer 168 and non-inverter buffer 170
Are three-state outputs. That is, when the output enable terminals of the buffers 168 and 170 have a low level voltage, the output terminals are in a high impedance state. The output enable terminal of the buffer 170 is connected to the output terminal of the inverter 172, and the input terminal of the inverter 172 and the inverter buffer 168.
Output enable terminal of the system control circuit 22
And an oscillation control signal 222 is input from the system control circuit 22.

The output terminals of the inverter buffer 168 and the non-inverter buffer 170 are connected to the base terminal of the transistor 160 via the resistor 162. The collector terminals of the transistors 160 and 164 are connected to the resistor 1
It is connected to the output terminal of the D / A converter 152 via 56 and 158. The collector terminal of the transistor 160 is connected to the transparent electrode 78a of the color temperature conversion filter 67, and the collector terminal of the transistor 164 is connected to the transparent electrode 78b. The D / A converter 152 includes a reference voltage power supply 154.
And the system control circuit 22 are connected. Then, the square wave signal 2 applied to the color temperature conversion filter 67
Digital data 220 for adjusting the amplitudes of 16 and 218 is input from the system control circuit 22.

FIG. 6 shows a GH liquid crystal cell as a color temperature conversion filter 67 (FIG. 1) used in the present embodiment. In this figure, a liquid crystal cell 69 is provided with a liquid crystal substance 77 composed of elongated liquid crystal molecules and a glass substrate 21 having a transparent electrode 78a.
a and a glass substrate 21b having a transparent electrode 78b. Xenon tube 4 of glass substrate 21a
A polarizing plate 93a is in close contact with the surface for 1. The light emitted from the xenon tube 41 is limited to one linearly polarized light by the polarizing plate 93a.

The GH liquid crystal cell 69 has, for example, a homogeneous alignment (elongated liquid crystal molecules are oriented in the horizontal direction with respect to the glass substrate surface sandwiching the liquid crystal molecules) and a positive dielectric anisotropy (elongated liquid crystal molecules). Dissolves the elongated dye molecules in the liquid crystal (the dielectric constant in the long axis direction is larger than the dielectric constant in the direction perpendicular to it), and the light absorption characteristics of the dye molecules oscillate in the rectangular axis direction rather than the long axis direction. Use a material that strongly absorbs light.

The operation of this embodiment will be described. When charging start signal S2 is input to charging circuit 50, strobe device 2
5 or a high voltage signal obtained by increasing the power supply voltage of a battery or the like provided in the still video camera main body is applied from the charging circuit 50 to the main capacitor C5 and the capacitor C7. As a result, electric charges are gradually stored in the capacitors C5 and C7. When the potential difference between both ends of the main capacitor C5 becomes a predetermined potential difference due to charge accumulation, a current flows through the neon tube 132, and a charge completion signal S23 is output to the system control circuit 22.

When the release switch 33 is fully pressed,
A light emission trigger signal S24 is output from the system control circuit 22 according to a shooting processing timing chart described later. This light emission trigger signal S24 is output from the flash device 2
5, and the thyristor 124 is turned on. When the thyristor 124 is turned on, the electric charge stored in the capacitor C7 is discharged, a high voltage is induced in the high-voltage side coil of the trigger transformer T3, and applied to the trigger electrode of the xenon tube 41. By applying a high voltage to the trigger electrode, the xenon gas in the xenon tube 41 is ionized, and the resistance between the anode and the cathode of the xenon tube 41 rapidly decreases.
Thus, the electric charge stored in the main capacitor C5 is discharged in the xenon tube 41, and a flash is generated.
The light F2 emitted from the xenon tube 41 by the flash is
The light is irradiated on the subject 35 through the color temperature conversion filter 67.

On the other hand, before the flash device 25 starts emitting light,
An appropriate integral value S9 is set in the flash light control circuit 29 by the system control circuit 22. Then, in synchronization with the input of the light emission trigger signal S24 to the flash charging / light emission circuit 58, the integration start signal S5 is input to the flash light control circuit 29. The switch 66 is turned off by the integration start signal S5, and the photocurrent of the photometric sensor 28 that changes with the reflected light F4 from the subject 35 is integrated by the operational amplifier 60 having the capacitor 64. On the other hand, the target level voltage is applied to the positive phase input terminal of the comparator 61 by the appropriate integration value S9 input from the system control circuit 22 to the D / A converter 62. This applied voltage value and the output signal S7 of the operational amplifier 60 are
When the difference from the voltage value of the comparator 6 becomes a predetermined value, the comparator 6
1 outputs a quench signal S6. In response to the quench signal S6, the thyristor 136 of the strobe device 25 is turned on, and the electric charge of the main capacitor C5 used for light emission of the xenon tube 41 is discharged through the thyristor 136. Thus, the flash of the xenon tube 41 is stopped.

The operation of the filter control circuit 63 will be described. The digital data 220 input from the system control circuit 22 to the filter control circuit 63 is D / D
The signal is converted into an analog signal by the A converter 152 and applied to the collector terminals of the transistors 160 and 164.
Thereby, the amplitude values of the rectangular wave signals 216 and 218 are adjusted. The rectangular wave signal output from the oscillation circuit 150 is applied to the inverter buffer 168, the non-inverter buffer 170, and the base terminal of the transistor 164. At this time, if the control signal 222 input from the system control circuit 22 is a low level signal, the output of the non-inverter buffer 170 is activated,
The signals applied to the base terminals of the transistors 160 and 164 are in phase. For this reason, the transparent electrodes 78a, 78
The rectangular wave signals 216 and 218 applied to b respectively have the same phase, and no potential difference occurs in the transmission optical axis direction of the liquid crystal substance 77.

On the other hand, when the control signal 222 is a high level signal, the output of the inverter buffer 168 becomes active, and the signal applied to the base terminal of the transistor 164 and the signal applied to the base terminal of the transistor 160 are changed. The phase is reversed. Thereby, the transparent electrode 7
The phases of the rectangular wave signals 216 and 218 applied to 8a and 78b are opposite to each other, and a potential difference occurs in the transmitted light axis direction of the liquid crystal substance 77.

If there is no potential difference on both sides of the liquid crystal material 77, FIG.
As shown in (a), the polarization direction of the incident light and the alignment direction of the liquid crystal molecules, that is, the major axis direction of the dye molecules match.
Therefore, since the direction in which the light absorption of the dye molecule is strong and the plane of polarization of the incident light are orthogonal to each other, light absorption of the transmitted light does not occur, and the light of the xenon tube 41 is emitted toward the subject 35 as it is.

On the other hand, when a potential difference equal to or more than a predetermined value is applied to both sides of the liquid crystal substance 77, the liquid crystal molecules are changed from a homogeneous alignment state to a homeotropic alignment state as shown in FIG. The arrangement direction changes in the direction of the electric field. As a result, the polarization direction of the incident light is orthogonal to the major axis direction of the dye molecules, so that light absorption by the dye molecules occurs, the transmitted light from the xenon tube 41 is colored, and the spectral distribution of the light F2 changes, The color temperature changes.

The degree of change of the liquid crystal molecules from the homogeneous alignment state to the homeotropic alignment state can be adjusted by the magnitude of the voltage applied to both sides of the liquid crystal substance 77. Can be. For this reason, the xenon tube 4
The color temperature of the light emitted from the light source 1 can be adjusted.
For example, if the dye molecules dissolved in the liquid crystal can absorb visible light having a short wavelength, the color temperature of strobe light emission can be gradually lowered by increasing the applied voltage.

Next, a description will be given of the entire process of flash photography in a still video camera. FIG. 7 is a timing chart of a shooting process of the still video camera according to the present embodiment when strobe light is emitted.

When the release switch 33 is half-pressed (step D20), the brightness of the subject 35 is measured by the photometric sensor 30 and the photometric circuit 31 under the control of the system control circuit 22. Then, an exposure value is calculated from the photometric value by the exposure calculation circuit 32 and input to the system control circuit 22. The system control circuit 22 determines the opening amount of the aperture 20 and the opening time of the electronic shutter in the CCD 11 based on the brightness value or the exposure value of the subject 35 (step D21).

Next, when the release switch 33 is fully pressed continuously from the half-pressed state (step D22), the subject 35 is controlled by the colorimetric sensor 23 and the colorimetric circuit 24 under the control of the system control circuit 22. The color temperature of the ambient light is measured (Step D23), and the measured color temperature data is input to the system control circuit 22. The system control circuit 22 outputs digital data 220 to the filter control circuit 63 in order to determine the potential difference applied to the liquid crystal substance 77 based on the measured color temperature data (step D24).

In order to adjust the gain of the R signal and the B signal input from the CCD 11 based on the measured color temperature of the light F4 from the subject 35 input from the colorimetric circuit 24,
Digital data to be output to the D / A converters 86 and 88 is set (step D25). Based on the measured color temperature data, a proper integration value S9 for adjusting the flash emission time is obtained and input to the D / A converter 62 of the flash light control circuit 29 (step D26).

On the other hand, if it is determined from the photometric result of the photometric sensor 30 or the measured color temperature data that the ambient light of the subject 35 is darker than a predetermined brightness, the control signal 222 is output.
Is set to the low level, and the original light of the xenon tube 41 is irradiated directly to the subject 35. Furthermore, a white balance (amplifier 8) adapted to the primary color temperature of the strobe light
4 and 87) and the strobe light control level (setting of the appropriate integral value S9). On the other hand, before the release switch is fully depressed, a charge start signal S2 is output to the strobe device 25 in accordance with a result of determination as to whether or not the charge completion signal S23 has been input from the strobe charge / light emission circuit 58, The electric charge required for light emission is stored in the main capacitor C5.

When the adjustment of the filter control circuit 63, the flash light control circuit 29, and the amplifiers 84 and 87 is performed in this manner, the system control circuit 22 controls the aperture of the aperture 20 via the aperture drive circuit 27. At the same time (step D27), the CCD 1
The first electronic shutter is opened (step D28). The electronic shutter is opened, and a light emission trigger signal S24 is output to the strobe device 25 to start light emission of the xenon tube 41 (step D29).

In synchronization with the output of the light emission trigger signal S24, the system control circuit 22 outputs an integration start signal S5 to the strobe light control circuit 29 (step D3).
0), the dimming control by the flash dimming circuit 29 is started. That is, the reflected light F4 from the subject 35 due to the strobe light is integrated over time. When the reflected light F4 reaches the target light amount (step D31), the quench signal S6 is input from the strobe light control circuit 29 to the strobe device 25 to stop the strobe light emission (step D3).
2).

When the strobe light emission is stopped in this way, the switch 66 is closed (step D33), and the integration operation of the operational amplifier 60 is stopped. In addition, CCD1
The first electronic shutter is closed (step D34), and the aperture 20 is also closed (step D35). Then, while the electronic shutter is open, the charge stored in the CCD 11 is read out and output to the signal processing circuit 15 (step D36).

As described above, when the ambient light has a predetermined brightness or more, the color temperature of the light emitted from the xenon tube 41 is changed to the color temperature of the ambient light of the subject 35 measured by the colorimetric sensor 23. At the same time, the gain of the R signal and the B signal read from the CCD 11 is adjusted to adjust the white balance. When the ambient light is darker than a predetermined brightness, the color temperature of the light emitted from the xenon tube 41 is not adjusted, and the white balance and the light control level of the strobe are adjusted based on the emitted color temperature. This makes it possible to always make optimal white balance adjustment under various shooting environments.

FIGS. 8A and 8B are cross-sectional views of a second example of the color temperature conversion filter 67 provided in the strobe device 25 of the first embodiment for converting the emission color temperature. FIG. 9A is a front view of the light emitting surface of the strobe device shown in FIGS. In these figures, a reflector 89 that efficiently reflects light emitted from the xenon tube 41 toward the front of the strobe device is provided around the back of the xenon tube 41. This reflector 89
Is provided with a diffusion plate 90 formed by a chemical treatment. An amber filter coat 92 for lowering the color temperature of light emitted from the xenon tube 41 is attached to one surface of the central portion 91 of the diffusion plate 90 by a process such as vapor deposition. A liquid crystal cell 69 is mounted outside the diffusion plate 90.

The liquid crystal cell 69 includes transparent electrodes 78a and 78b.
And a liquid crystal substance 77 provided between the transparent electrodes 78a and 78b and having undergone a homogeneous alignment treatment. The alignment of the liquid crystal molecules in the major axis direction is twisted between the substrates 21a and 21b, and forms a TN (twisted nematic) liquid crystal cell. On both sides of the liquid crystal cell 69, a polarizing plate 93a and an analyzing plate 93b whose polarizing planes are orthogonal to each other are attached in close contact. As shown in FIG. 8A, the transparent electrodes 78a and 78b are formed only partially so that a voltage is applied to the liquid crystal substance 77 in the central portion 91 where the filter coat 92 exists.

In the color temperature conversion filter 67 shown in FIG. 8A, the light radiated from the xenon tube 41 and transmitted through the diffusion plate 90 is transmitted by the polarizing plate 93a to the liquid crystal molecule alignment direction on the surface of the glass substrate 21a of the liquid crystal cell 69. Only the light of the linearly polarized light whose polarization direction coincides with that of the liquid crystal material 77 is incident on the liquid crystal substance 77. The light incident on the liquid crystal substance 77 is polarized by approximately 90 ° along the twist of the liquid crystal molecules, and can be transmitted through the analyzer 93b as it is.

When a potential difference is applied only between the transparent electrodes 78a and 78b of the central portion 91 of the liquid crystal cell 69 as shown in FIG. The sequence changes to a homeotropic sequence. For this reason, most of the light in the central portion 91 radiated from the xenon tube 41 and transmitted through the filter coat 92 cannot rotate its polarization plane.
b cannot be transmitted.

Therefore, the transparent electrodes 78a in the central portion 91,
If no potential difference is applied to 78b, as shown in FIG.
As for the light emitted from the xenon tube 41, the light of the central portion 91 that has passed through the filter coat 92 and the light of the peripheral portions 94a and 94b that do not pass through the filter coat 92 pass through the liquid crystal cell 69 and are emitted. Filter coat 92
The light that has passed through is reduced in color temperature and becomes yellow light. Peripheral part 9 that does not transmit through filter coat 92
The light of 4a and 94b is irradiated with strobe light of the primary color temperature as it is. As a result, the entire color temperature of the light emitted from the strobe device is reduced by the sum of the transmitted light whose color temperature has been reduced and the transmitted light whose color temperature has not been reduced.

Conversely, as shown in FIG. 8A, when a potential difference is applied to the central portions 91 of the transparent electrodes 78a and 78b of the liquid crystal cell 69, as described above, light 9 due to the liquid crystal molecules is generated.
Since the 0 ° optical rotation disappears, most of the transmitted light linearly polarized by the polarizing plate 93a cannot pass through the light analyzing plate 93b. Therefore, most of the light whose color temperature has been lowered by the filter coat 92 is not emitted to the outside. If the light whose color temperature is lowered is not emitted, the entire light emitted from the xenon tube 41 has a higher color temperature and a color with reduced yellow tint as compared to FIG.

FIG. 8C is a cross-sectional view of a third configuration example of the color temperature conversion filter 67 provided in the strobe device 25 of the first embodiment. FIG. 9A is a front view of the third configuration example. In these figures, the transparent electrode 78a
The transparent electrode 78b is not provided in the central portion 91 where the filter coat 92 is located, but is provided only in the peripheral portions 94a and 94b of the liquid crystal substance 77. The other xenon tube 41, reflector 89, diffusion plate 90, filter coat 92, polarizing plate 93a and analyzer 93b are shown in FIG.
This is the same configuration as (A) and (A).

In the third configuration example of the filter 67,
When a potential difference is applied to the peripheral portions 94a and 94b of the transparent electrodes 78a and 78b, as described above, the liquid crystal substance
The molecular orientation of No. 7 is arranged in the direction of the electric field, the 90-degree optical rotation of the transmitted light by the liquid crystal substance disappears, and the light cannot pass through the analyzer 93b. For this reason, most of the light in which the color temperature of the peripheral portions 94a and 94b has not been changed cannot pass through the liquid crystal cell 69, and the entire radiated light of the xenon tube 41 is as shown in FIG.
The color temperature is further reduced as compared with (a).

FIG. 10A shows a fourth configuration example of the color temperature conversion filter 67 in the first embodiment. In this figure, amber filter coats 96a, 96b, 96c are partially adhered to one surface of the diffusion plate 90. The transparent electrodes 78a and 78b are configured such that a voltage can be applied only to the portions 95a, 95b and 95c of the liquid crystal material 77 facing the filter coats 96a, 96b and 96c. The configuration of the xenon tube 41 and the reflector 89 is the same as the color temperature conversion filter 67 shown in FIG.
Is the same as

In the fourth configuration example of the filter 67,
The location where the voltage of the liquid crystal cell 69 is applied is defined by the portions 95a, 95b, where the filter coats 96a, 96b, 96c exist.
95c. Thereby, the filter coat 96a,
Most of the light whose color temperature has been lowered by 96b and 96c is shielded, and the entire color temperature of the light emitted from the xenon tube 41 becomes relatively higher than when no voltage is applied. Further, the filter 67 of the fourth configuration example
Since the filter coat portion is dispersed on the surface of the diffusion plate 90, it is possible to reduce light projection unevenness that occurs in a subject in close-up shooting as compared with the second configuration example in FIG.

FIG. 10A shows a fifth configuration example of the color temperature conversion filter 67 mounted on the strobe device 25 of the first embodiment. In this figure, the divided filter coats 98a, 98b, 98c are intensively attached to the central portion 99 on one side of the diffusion plate 90. Further, the polarizing plate 97a and the analyzing plate 97b are attached only to the central portion 99 of the liquid crystal cell 69, and the peripheral portions 42a and 42b which do not reduce the light emitted from the xenon tube 41 by the polarizing plate 97a, the analyzing plate 97b and the filter coat. Provide. In addition, the transparent electrode 7
8a, 78b are filter coats 98a, 98b, 9
8c, portions 99a, 99b of the liquid crystal cell 69,
It is configured such that a voltage can be applied to 99c. The configurations of the xenon tube 41 and the reflector 89 are the same as those of the filter 67 of FIG.

In the fifth configuration example of the filter 67, as in the fourth configuration example, the filter coats 98a and 98 are provided.
A voltage is applied only to the liquid crystal substance 77 in the portions 8b and 98c to form light-shielding portions 99a, 99b and 99c, and to shield most of the light transmitted through the filter coats 98a, 98b and 98c. Thereby, the transparent electrodes 78a, 78b
The color temperature of the entire light emitted from the strobe device can be made relatively higher than when no voltage is applied. Further, since the areas of the polarizing plate 97a and the analyzing plate 97b are made smaller than those of the second to fourth configuration examples, dimming of light emitted from the xenon tube 41 by the polarizing plate 97a and the analyzing plate 97b is reduced. So you can
The reduction of the guide number of the strobe device 25 itself can be relatively reduced.

The transparent electrodes 78a and 78b in the filters 67 of the above-described second to fifth configuration examples are provided only in the portions to which the voltage of the liquid crystal substance 77 is to be applied. You may. For example, the transparent electrode 78
“a” is constituted by a plurality of band-shaped display electrodes arranged in the Y-axis direction, and the other transparent electrode 78b is constituted by a plurality of band-shaped scan electrodes arranged in the X-axis direction. A matrix is formed by these transparent electrodes 78a and 78b on both surfaces, and a display electrode and a scanning electrode of the transparent electrodes 78a and 78b are selected and a voltage is applied. Thus, various portions of the liquid crystal cell 69 can be selected and applied with a voltage, and the light transmission of the portion to which the voltage is applied can be controlled. This makes it possible to adjust not only the color temperature of the strobe light but also the entire projected light amount.

FIGS. 11A and 11B show a sixth configuration example of the filter 67 provided in the strobe device 25 of the first embodiment. In this figure, similarly to the filter 67 of the second to fifth configuration examples, the xenon tube 41 and the reflector 8
9 are provided on both sides of the reflector 89, and a driving device including a motor or the like (not shown) and the rotating shaft 1
02a, 102b
0 and 101 are provided. This rotating body 100, 10
1 includes a plurality of filter portions 104a, 104b, 104c, and 1 having gradually different densities as shown in FIG.
A single filter film 103 made of 04d is wound. By the operation of winding the filter film in the left and right directions of the rotating bodies 100 and 101, the filter portion 104 is formed.
One of a, 104b, 104c, and 104d covers the front surface of the xenon tube 41. Each filter portion 104a-10
Reference numeral 4d denotes an amber color filter.
The density gradually decreases from 04a to the filter portion 104d. Thereby, the filter portion 104a
When the filter portion 104d covers the front surface of the xenon tube 41, the color temperature of the strobe light can be further increased as compared with the case where the filter portion 104d covers the front surface of the xenon tube 41.

FIG. 11C shows a seventh configuration example of the color temperature conversion filter 67 used in the strobe device 25 of the first embodiment. In this figure, the filter film 103 shown in FIG. Rotator 100,
By the rotation of 101, each of the filter portions 104a to 104d is moved so as to surround the front and rear of the xenon tube 41. As in the sixth configuration example, the filter film 103 used in the seventh configuration example of the filter 67 has a gradually decreasing filter density.

In the filters 67 of the sixth and seventh configuration examples,
By rotating the rotating bodies 100 and 101, the filter portions 104a and 104a of the filter film 103 covering the front surface of the xenon tube 41
By selecting 04b, 104c, and 104d, the color temperature of the strobe device is changed. That is, the emission color temperature of the xenon tube 41 can be reduced as the density of the filter color is increased. Further, the density change of the filter film 103 may be made continuous, and in this case, the variable amount of the color temperature can be made continuous.

FIG. 12 shows a flash device 2 according to the first embodiment.
18 shows an eighth configuration example of the filter 67 provided in the fifth embodiment. In this figure, a gear 1 rotated by a driving device such as a motor (not shown) is provided in a housing 105 of the strobe device.
Reference numeral 06 is provided, and a slider 107 having gear teeth meshing with the gear 106 on the rear surface is provided so as to move in the housing 105 in parallel. A filter 108 is provided upright on the slider 107. The rotation of the gear 106 causes the filter 108 to slide left and right, and
9 covers the front opening 105a. That is, in the eighth configuration example, the emission color temperature of the xenon tube 41 is adjusted depending on whether or not the filter 108 covers the opening 105a.

In the sixth, seventh, and eighth configuration examples, the diffusion plate 90 may be provided before or after the filter film 103 or the filter 108. This makes it possible to irradiate the strobe light over a wider area.

Each of the filters 6 shown in FIGS.
7, the filter coats 92, 96a, 96b,
The filter colors 96c, 98a, 98b, and 98c are not limited to amber, but may be red filters that transmit only light having a longer wavelength. A blue filter may be used to increase the color temperature of the strobe light. The filter 67 of the fourth or fifth configuration example in FIG. 10 having a plurality of filter coats to be attached to the diffusion plate 90
, Filter coats having different transmitted light distributions may be combined, respectively, or the filter 67 of the second configuration example of FIG. 8A may cause unevenness in the spectral distribution of transmitted light of one filter coat. You may have it. For example, the thickness of the filter coat 92 is uneven or multi-layered to make the filter color spotted or mottled.
Furthermore, if the central portion 91 for applying a voltage to the transparent electrodes 78a and 78b is further subdivided and the light-shielding central portion 91 is subdivided, the range of adjustment of the emission color temperature of the strobe light can be further increased.

In the filters 67 of the fourth and fifth configuration examples shown in FIG. 10, the portions to which the voltage is applied to block the light are changed to the portions 95a to 95c, 99a to 99c corresponding to the filter coats 96a to 96c and 98a to 98c. However, as shown in FIG. 8C, a voltage may be applied to a portion without a filter coat, for example, peripheral portions 42a and 42b to block light from the xenon tube 41. Polarizing plate 9
The polarizing planes 3a and 93b are orthogonal to each other in each of the filters 67 in FIGS. 8 and 10, but may be arranged so as to be parallel. Is opposite to the above embodiment. That is,
When a voltage is applied, the liquid crystal molecules of the TN type liquid crystal cell become homeotropically aligned, so that the twist of the polarization plane of the transmitted light disappears, and the linearly polarized light transmitted through the polarizing plate 93a passes directly through the analyzing plate 93b. can do. Therefore,
The color temperature control of the strobe light by ON / OFF of the applied voltage is opposite to the above.

The liquid crystal substance 77 is also shown in FIGS.
In each of the filters, a liquid crystal material having a positive dielectric anisotropy is used, and a glass substrate 21 having undergone a homogeneous alignment treatment is used.
Although the twisted nematic cell was formed by a and 21b, any liquid crystal material capable of switching between a transparent state and an opaque state by ON / OFF of a voltage application may be used. It doesn't have to be big. Therefore, a liquid crystal cell which becomes opaque when no applied voltage is applied, such as a liquid crystal cell having a positive dielectric anisotropy and having a phase transition effect using a cholesteric liquid crystal or a chiral nematic liquid crystal having a relatively long helical pitch. You may.

Further, the filter 6 of the first configuration example shown in FIG.
In FIG. 7, a GH liquid crystal cell was used to change the color temperature of light emitted from the xenon tube 41.
Negative dielectric anisotropy (elongated liquid crystal molecules) with homeotropic (elongated liquid crystal molecules are oriented perpendicular to the glass substrate surface sandwiching the liquid crystal molecules) with electric field controlled birefringence (ECB) effect (The permittivity in the major axis direction is smaller than the permittivity in the direction perpendicular to the nematic liquid crystal cell) is placed between the orthogonal polarizers, and the color of the transmitted light is changed according to the magnitude of the applied voltage. You may.

That is, in a liquid crystal cell having the ECB effect,
If no voltage is applied, the long axis direction of the liquid crystal molecules coincides with the optical axis of the incident light, so that the liquid crystal cell does not exhibit birefringence, and light cannot be transmitted by the orthogonal polarizing plates. However, when a voltage is applied, the liquid crystal molecules are tilted in a direction perpendicular to the electric field due to Frederick transition, birefringence occurs in the liquid crystal cell, and a part of the incident light can pass through the analyzer. Since this birefringence can be controlled by the magnitude of the electric field, the hue of the transmitted light can be changed by the interference effect caused by the magnitude of the applied voltage, thereby adjusting the color temperature of the transmitted light from the xenon tube 41. be able to.

Further, as the GH liquid crystal cell itself, a GH liquid crystal cell having a cholesteric nematic phase transition effect, such as a white tailor type liquid crystal panel having no polarizing plate, may be used. In this white tailored GH liquid crystal cell, when no voltage is applied, the liquid crystal molecules assume a cholesteric liquid crystal state, and the dye molecules oriented in various directions in a spiral form have a strong absorption effect. , The transmitted light from the xenon tube 41 can be colored. On the other hand, when a voltage is applied, the liquid crystal molecules are in a homeotropic alignment nematic state, so that the dye molecules are also arranged in the direction of the electric field, the absorption effect is lost, and the xenon tube 41
Light is transmitted as it is. Further, the dielectric anisotropy of the liquid crystal molecules used in the GH liquid crystal cell may be not only positive but also negative. Negative dielectric anisotropy is sandwiched between substrates subjected to homeotropic alignment treatment,
When a dye molecule in which the light absorption effect of molecules is strong in the major axis direction is dissolved in the liquid crystal, the absorption effect acts strongly on the transmitted light when a voltage is applied, and the emitted light transmitted from the xenon tube 41 is colored. .

Further, as shown in FIG. 13A, a plurality of GH liquid crystal cells 180 to 182 in each of which dye molecules having different light absorption spectral characteristics are dissolved, and a single polarizing plate 9
The composite liquid crystal cell having the liquid crystal cell 3a attached thereto may be used. In this case, by selecting the GH liquid crystal cell to which a voltage is applied, the coloring of light transmitted through the entire liquid crystal cell can be freely selected, and the strobe emission can be selected. The color temperature adjustment range can be made larger. FIG. 13A includes a TN liquid crystal cell 183, a birefringent plate 184, two polarizing plates 93a and an analyzing plate 93b arranged so that the linear polarization directions of transmitted light are orthogonal or parallel. 3 shows a color temperature conversion filter. In this example, although the transmitted light of a unique color is obtained by the retardation that can be multiplied by the thickness of the birefringent plate 184 and the birefringence of the plate, complementary colors are obtained by ON / OFF of the voltage applied to the TN liquid crystal cell. Two related transmitted lights are obtained.

As described above, by using a GH liquid crystal cell in which a dye molecule is dissolved or a TN liquid crystal cell having a filter coat, the color temperature of strobe light can be adjusted. Therefore, the liquid crystal cell as the filter used for adjusting the color temperature of the strobe light is not particularly limited to the above-described one. If the amount of transmitted light can be adjusted by applying a voltage, the liquid crystal cell can be adjusted in front of or behind the liquid crystal cell. , A filter having a predetermined color may be provided. Also,
In the case of a GH liquid crystal cell capable of directly changing the color of transmitted light, the color temperature of strobe light emission can be adjusted by selecting dye molecules dissolved in the liquid crystal.

As for the configuration of the colorimetric sensor 23 and the photometric sensor 30, for example, each sensor may be composed of a plurality of light receiving elements, and the whole image photographed by the CCD 11 may be divided to perform colorimetry and photometry. And each sensor 2
A light guide means such as a prism or a reflection mirror may be provided in front of 3, 30 so that light entering the CCD 11 via the imaging optical system lens 36 can be measured and measured.

According to each of the above embodiments, in the still video camera shooting using the strobe light, even if the color temperature of the strobe light and the color temperature of the ambient light of the subject 35 are significantly different, the color temperature of the strobe light Is provided with a color temperature conversion filter in front of the strobe light emitting tube so as to tune the color temperature of the ambient light, so that a photographed image with more optimal white balance can be obtained. Furthermore, even if the photographing environment is dark and the color temperature of the subject cannot be measured sufficiently by the colorimetric sensor based on the photometric results from the photometric sensor, this white balance control is stored in advance in the flash light when the color temperature is not adjusted. Since the determination is performed based on the color temperature data, it is possible to prevent a white balance deviation from occurring due to an incorrect color measurement result.

FIG. 14 shows a strobe device 25 according to the second embodiment.
FIG. 2 is a block circuit diagram of a still video camera provided with the camera.
In this figure, a ray F4 coming from the subject 35 is
The light is guided to the CCD 11 (solid-state imaging device) through the imaging optical system lens 36 and the aperture 20, and a subject image is formed on the CCD 11. The CCD 11 has an image sensor driving circuit 26
Are connected, and an image signal (here, R, G, B signals) is generated by a drive signal from the image sensor drive circuit 26.
Is input from the CCD 11 to the correlated double sampling (CDS) circuit 12. The charge storage time of the CCD 11, that is, the electronic shutter time is controlled by the system control circuit 22.

In the CDS circuit 12, reset noise is removed from the image signal. Then, an image signal from which reset noise has been removed is input from the CDS circuit 12 to the color separation circuit 13. The color separation circuit 13, the luminance signal from the image signal Y and two color difference signals _{(R-Y) 0, (} B-Y) 0 and are separated product.

The color difference signals (RY) ₀ , (BY) ₀
Is input to a white balance adjustment circuit 14, where white balance adjustment for adjusting the gain of the color difference signal is performed. The color difference signals (RY) ₁ and (BY) ₁ that have been subjected to white balance adjustment are subjected to predetermined processing in the signal processing circuit 15 together with the luminance signal Y output from the color separation circuit 13. After that, the interface circuit 16
Is output to the display device 17 via the PC and displayed on the screen. Further, these signals are output from the signal processing circuit 15 to the F
The signal is also supplied to the M modulation circuit 18, FM-modulated, and input to the recording circuit 19. The recording circuit 19 is connected to a magnetic head (not shown) that traces a track on the signal recording surface of the flexible disk M. When the shutter release switch 33 is turned on, the recording circuit 19 operates under the control of the system control circuit 22 to thereby control the brightness. The signal and the color difference signal are recorded on the flexible disk M in a color difference line sequential manner.

To detect the color temperature of external light, a colorimetric sensor 23 and a colorimetric control circuit 24 are provided. The colorimetric sensor 23 includes a plurality of photoelectric conversion elements each including a filter having a different spectral distribution of transmitted light. The intensity of each of the R, G, and B components of the external light is detected by the colorimetric sensor 23, and the colorimetric control circuit 24 calculates the R / G signal and the B / G signal. These R / G signals and B / G
The signal is input to the white balance adjustment circuit 14 and the system control circuit 22, respectively. The proportions of the R component and the B component in white change with the color temperature, and the G component also changes with the color temperature. However, even if the R component, the B component, and the G component have the same color temperature, they change depending on brightness. On the other hand, the R / G signal and the B / G signal are not affected by the brightness, and a value corresponding to the color temperature on a one-to-one basis is obtained (FIG. 2). Therefore, the color temperature is detected by obtaining the R / G signal and the B / G signal. In the white balance adjustment circuit 14, a color difference signal (R-
The amplification degree for each of Y) ₀ and (B−Y) ₀ is adjusted, and white balance adjustment is performed.

The flash dimming circuit 29 has a photometric sensor 28
Is connected, and the light amount of the strobe light emitted from the strobe device 25 and reflected by the subject 35 is measured using the photometric sensor 28, and the system control circuit 2
A light control signal (quenching signal) is output to 2. The photometric circuit 31 is connected to the exposure calculation circuit 32, and the photometric sensor 30 including a photoelectric conversion element is connected to the photometric circuit 31. The subject 3 is measured by the photometric sensor 30 and the photometric circuit 31.
5 is measured, and an exposure calculation circuit 32 performs an exposure calculation from the photometric value. The release switch 33 is
As described later, photometry, colorimetry, the opening amount of the aperture 20 and C
The system control circuit 22 is instructed to start photographing processing for performing electronic shutter control of the CD 11 and the like.

The system control circuit 22 controls the strobe device 25 based on the R / G signal and the B / G signal input from the colorimetric control circuit 24. As will be described later, there are two types of strobe devices 25: a case where two flash tubes are provided, and a case where one flash tube is provided.
In either case, the system control circuit 22 controls the emission color temperature of the strobe device 25 to match the color temperature of light existing around the subject 35. Further, a timer circuit 34 is connected to the system control circuit 22, and is used as a balance control factor of the light emission time of each xenon tube of the strobe device 25 described later. Time data is input to the timer circuit 34, and the timer circuit 34 sends the data to the system control circuit 2.
2, a time-over signal S14 based on the time measurement result is input.

The strobe light control circuit 29 in FIG. 14 is the same as that shown in FIG. FIG. 15 shows a second embodiment of the strobe device 25 connected to the system control circuit 22. The strobe device 25 of the second embodiment shown in FIG.
4 are provided. The cathode terminals of the xenon tubes 41 and 45 are insulated gate bipolar transistors (IGBT) 52,
It is connected to the ground common signal line S10 via 53.
Trigger circuits 54 and 55 are connected to the trigger electrodes of the xenon tubes 41 and 45, respectively. Each trigger circuit 5
Reference numerals 4 and 55 include resistors R5 and R6, trigger capacitors C1 and C2, and trigger transformers T1 and T2, respectively. The trigger capacitors C1 and C2 are connected to one ends of the resistors R5 and R6, the respective collector terminals of the IGBTs 52 and 53, and the cathode terminals of the xenon tubes 41 and 45. , C2 are discharged, and a trigger signal is generated in the high-voltage side coils of the trigger transformers T1, T2.

Main capacitors C 3 and C 4 dedicated to each xenon tube are connected in parallel via IGBTs 52 and 53 between the anode and cathode terminals of the xenon tubes 41 and 45. When the IGBTs 52 and 53 are turned on, trigger signals are generated by the trigger transformers T1 and T2 and applied to the xenon tubes 41 and 45, respectively. As a result, strobe light is generated using the electric charges stored in the main capacitors C3 and C4.

The anode terminal of the xenon tube 41 is connected to one end of the switch 84b of the photo MOS relay 85b by a signal line S18, and the anode terminal of the xenon tube 45 is connected to the photo MOS relay 85a by a signal line S12.
Is connected to one end of the switch unit 84a. The other ends of the switches 84a and 84b are connected to the cathode terminal of the diode D1 and one end of the resistor R8 by a signal line S19. The anode terminal of the diode D1 is connected to the charging circuit 50, and in response to a charging start signal S2 input from the system control circuit 22 to the charging circuit 50, a pulsed high-voltage charging signal from the charging circuit 50 is supplied to each switch unit. 84a and 84b. It is applied to each of the main capacitors C3 and C4 via the photo MOS relays 85a and 85b that are turned on, and the light-emitting charges are accumulated.

By the action of the diode D1, when one of the switch portions 84a, 84b is in the conductive state, the charge is prevented from flowing backward from the main capacitors C3, C4 to the charging circuit 50. The switch units 84a and 84b are configured by a photoelectric element, a bleeder resistor, a power MOSFET, and the like. The cathode terminals of the light emitting diodes 82a and 82b of the photo MOS relays 85a and 85b are both connected to the common ground signal line S10, and the anode terminals of the light emitting diodes 82a and 82b are connected to the system via resistors R10 and R11, respectively. Control circuit 2
2, the photo MOS relays 85a and 85b are turned on by the signals S20 and S21.

Further, resistors R8 and R9 are connected in series between the signal line S19 and the signal line S10.
A connection point P1 between the resistor 8 and the resistor R9 is connected to the A / D converter 56. The A / D converter 56 is connected to the system control circuit 22 so that the voltage at the connection point P1 becomes A / D.
The signal is D-converted and input to the system control circuit 22. Thereby, the charging voltage of the capacitors C3 and C4 can be measured indirectly.

FIGS. 16 to 22 show examples of the structure of the flash arc tubes (xenon tubes) 41 and 45. FIG. In the first configuration example shown in FIG. 16, the first and second xenon tubes 4 extending in the horizontal direction are provided inside a reflecting mirror 37 having a parabolic cross section.
1 and 45 are provided, and the first xenon tube 41 is disposed above the second xenon tube 45. The xenon tubes 41,
It is arranged in front of 45.

In the second configuration example shown in FIG. 17, the filters 40 and 44 have a cylindrical shape, and the xenon tubes 41 and
45 are fitted around each other. Other configurations are the same as those in FIG.

In the third configuration example shown in FIG. 18, the xenon tubes 41 and 45 are arranged at the focal point of the parabola of the reflecting mirror 37, and are provided on the same straight line. Also,
Filters 40 and 44 having a plate shape are disposed in front of xenon tubes 41 and 45, respectively.

In the fourth configuration example shown in FIG.
Similarly to 8, the xenon tubes 41 and 45 are disposed at the focal point of the parabola of the reflecting mirror 37, and are provided on the same straight line. The filters 40 and 44 have a cylindrical shape,
The xenon tubes 41 and 45 are fitted on the outer circumferences of the xenon tubes 41 and 45, respectively.

In the fifth configuration example shown in FIG. 20, two reflecting mirrors 38 and 39 each having a parabolic cross section are provided in the vertical direction, and extend horizontally at the focal positions of the reflecting mirrors 38 and 39. Xenon tubes 41 and 45 are provided, respectively. Also, the openings 38a, 39a of the respective reflecting mirrors 38, 39
Are provided with filters 40 and 44 each having a plate shape. The reflecting mirrors 38 and 39 are rotatable so that the filters 40 and 44 face inward, as indicated by arrows, thereby facilitating uniformizing the strobe light over the entire subject.

In the sixth configuration example shown in FIG. 21, each of the reflecting mirrors 38 and 39 is formed integrally,
Xenon tubes 4 respectively arranged at focal positions of 8, 39
Filters 40 and 44 are provided in front of 1, 45, respectively.

In the seventh configuration example shown in FIG. 22, first and second xenon tubes 41 and 45 extending in the horizontal direction are provided inside the reflecting mirror 37, and the first xenon tube 41 is It is arranged above the second xenon tube 45. A filter 40 having a flat plate shape is disposed in front of the first xenon tube 41 and the second xenon tube 4
No filter is provided in front of 5. That is, in this configuration example, it is equivalent to providing a filter having a transmittance of 100% for all light in front of the second xenon tube 45.

Next, the operation of the flash emission control in this embodiment will be described with reference to FIGS. FIG.
3 (a), (b) , (c) is a diagram showing different color difference signals of under color temperature (R-Y) _0, white balance characteristic by the gain adjustment (B-Y) _0.

In the state where the white balance adjustment is not performed, as shown in FIG.
, Two color difference signals (RY) ₀ and (BY) ₀
Indicate the same level and the level is 0, a white object is reproduced white at the color temperature KA,
The white balance will be correct. Therefore, when white balance adjustment (adjustment of the gains of the color difference signals (RY) ₀ and (BY) ₀ ) is performed on the color temperature KS of the strobe light, as shown in FIG. Color difference signal (R-
Y), the color difference signal (B-
The level of Y) is lowered, and the two color difference signals (RY) and (BY) both show 0 level with respect to the color temperature KS. However, at this time, if there is external light having a color temperature KB lower than that of the strobe light, two color difference signals (RY) and (BY) obtained from the subject illuminated by the external light.
Greatly deviates from the 0 level. That is, by performing white balance adjustment on the color temperature of the strobe light, the color of the subject affected by external light is reproduced as an unnatural color.

Therefore, in this embodiment, by controlling the light emission time of the xenon tubes 41 and 45 of the strobe device, respectively, the combined color temperature KBS of the strobe light is changed to the color temperature of the external light as shown in FIG. Approach KB,
White balance is performed based on the color temperature KB of the ambient light, thereby obtaining good color reproduction. That is, by approximating the combined color temperature of the strobe light to the color temperature KB of the external light, it is possible to prevent the appearance of an unnatural color biased toward the red or blue side in a part of the image. In a state where the color temperature cannot be measured when the external light is extremely weak, the white balance control may be performed by setting the strobe light to a predetermined combined color temperature Kbs. In addition, the first and second xenon tubes 4
Nos. 1 and 45 have basically the same performance, the light intensity changes over time after the start of light emission is the same, and a predetermined light amount can be obtained by controlling the light emission time.

FIG. 24 shows an example of the color temperature of various lights. As can be understood from FIG. 24, the color temperature of a normal strobe light is 6000 ° K to 7000 ° K, and sunlight, halogen Significantly higher than the color temperature of bulbs and incandescent bulbs. Further, as shown as an example in FIG. 25, the spectral distribution of the strobe light shows a high light intensity on the blue side with a short wavelength and a weak light intensity on the red side with a long wavelength. Therefore, the color temperature of light can be controlled by changing such a spectral distribution by the filters 40 and 44. For example, while suppressing the intensity of light with a short wavelength,
By increasing the intensity of light having a long wavelength, it is possible to obtain strobe light having a low color temperature, for example, close to light from an incandescent lamp.

The adjustment of the composite color temperature by controlling the emission of strobe light from the xenon tubes 41 and 45 will be described. Various filters can be used as the filters 40 and 44 used in the present embodiment. For example, the filter 44 corresponds to the solid line Q in FIG.
1, the filter 40 has a high spectral transmittance at a short wavelength, and the filter 40 has a high spectral transmittance at a long wavelength as shown by a solid line Q2. Here, for example, the light emission amount of the xenon tube 45 is made relatively small as shown by a broken line M1, and the light emission amount of the xenon tube 41 is made relatively large as shown by a solid line M2. The amount of light emitted from the xenon tube is determined by the duration of light emission and the potential difference applied between the anode and cathode terminals of the xenon tube at the start of light emission, that is, the main capacitors C3 and C4.
Is determined by the accumulated charge amount of

As a result, the light quantity of the strobe light actually irradiated through the filter 44 is proportional to the light quantity M1 multiplied by the transmittance Q1, and as shown by the solid line N1 in FIG. , Relatively small. The amount of strobe light emitted through the filter 41 is the amount of light M2
26 is multiplied by the transmittance Q2.
(C) As shown by the solid line N2, the distance becomes relatively large. Therefore, as shown by the two-dot chain line N3 in FIG. 26C, the spectral distribution of the strobe light applied to the subject has a small amount of light on the blue side with a short wavelength and a large amount of light on the red side with a long wavelength. That is, according to this example, strobe light having the same spectral distribution as light having a low color temperature can be obtained.
That is, the combined emission color temperature of the strobe device 25 can be adjusted.

A specific example of the filters 40 and 44 will be described. The filter 40 mounted in front of the light emitting surface of the xenon tube 41 has a color temperature conversion capacity T satisfying the following expression (4).
Let it be a color temperature conversion filter having a. Ta ≧ (10 ⁶ / Ka ′) − (10 ⁶ / Kc) [Mired] (4) When the color temperature conversion capability Ta takes a positive value, the filter 40 is an amber-based filter and has an absolute value. When the color temperature conversion capability Ta takes a negative value, the filter 40 is a blue-based filter, and as the absolute value increases, the blue color becomes more intense.

The filter 44 mounted in front of the light projecting surface of the xenon tube 45 is a color temperature conversion filter having a color temperature conversion capability Tb satisfying the following equation (5). Tb ≦ (10 ⁶ / Kb) − (10 ⁶ / Kc) [Mired] (5) When the color temperature conversion capability Tb takes a positive value, the filter 44 is an amber-based filter and the absolute value is When the color temperature conversion capability Tb takes a negative value, the filter 44 is a blue-based filter, and as the absolute value increases, the blue color becomes more intense.

That is, when the primary color temperature of the light that does not pass through the filters radiated by the xenon tubes 41 and 45 is the same Kc [K], a filter capable of converting the light to the color temperature Ka [K] is used. The filter 40 has a color temperature Kb
Filter 4 with the ability to convert to [K]
4.

The color temperatures Ka 'and Kb' [K] indicate the lower limit color temperature and the upper limit color temperature when controlling the combined color temperature of the light emitted from the xenon tubes 41 and 44 within the range G. Therefore, Ka ≦ Ka ′ ≦ G ≦ Kb ′ ≦ K
It becomes like b.

FIGS. 27 to 29 show the control range G, the primary color temperature Kc [K] of the xenon tubes 41 and 45, and the color temperature control range G.
And the color temperature Ka [K], Kb [K]. FIG. 27 shows the primary color temperature Kc of the xenon tubes 41 and 45.
FIG. 2 shows a case where [K] is equal to or higher than the color temperature Kb [K].
8 indicates that the primary color temperature Kc [K] is equal to the color temperature Ka [K] and Kb.
FIG. 29 shows the primary color temperature Kc when the value is between [K].
The case where [K] is equal to or lower than the color temperature Ka [K] is shown.

27, 28 and 29, the primary color temperature Kc [K] of the xenon tube is changed to the color temperature Ka.
The color temperature conversion capability Ta of the filter 40 for converting to [K] always satisfies the expression (4), and the primary color temperature Kc [K] is
b [K], the color temperature conversion ability Tb of the filter 44
Always satisfies equation (5).

FIGS. 30 and 31 show the flash emission control of the xenon tubes 41 and 45 when it is desired to control the combined color temperature of the light emitted from the flash device 25 to the color temperature Kd [K]. 3 shows how the composite color temperature changes with respect to a slight change in the color temperature. FIG. 30 shows the following (6)
Filter 40 having color temperature conversion ability Ta satisfying the following expression:
And a filter 44 having a color temperature conversion capability Tb satisfying the following equation (7). Ta = (10 ⁶ / Ka ′) − (10 ⁶ / Kc) [Mired] (6) Tb = (10 ⁶ / Kb ′) − (10 ⁶ / Kc) [Mired] (7)

In the case of FIG. 30, the primary color temperature Kc [K] of the xenon tube 41 that emits full light is filtered by the filter 40 so that the minimum color temperature Ka ′ [K] in the target range G of the color temperature control is obtained.
, And the primary color temperature Kc [K] of the xenon tube 45, which is also fully illuminated, is converted by the filter 44 into the maximum color temperature Kb ′ [K] of the color temperature control range G. FIG. 31 shows a color temperature conversion capability Ta ′ satisfying the following expression (8).
And a filter 44 having a color temperature conversion capability Tb ′ satisfying the following equation (9). That is, the color temperature conversion abilities Ta and Tb of the filters 40 and 44 in the case of FIG. 31 are relatively higher than in the case of FIG. Ta ′ = (10 ⁶ / Ka) − (10 ⁶ / Kc)> (10 ⁶ / Ka ′) − (10 ⁶ / Kc) [Mired] (8) where Ka <Ka ′ Tb ′ = (10 ⁶ / Kc) Kb) − (10 ⁶ / Kc) <(10 ⁶ / Kb ′) − (10 ⁶ / Kc) [Mired] (9) where Kb> Kb ′

In FIG. 31, the primary color temperature Kc [K] of the xenon tube 41 that has emitted full light is converted by the filter 40 into a color temperature Ka [K] lower than the color temperature Ka ′ [K]. The primary color temperature Kc [K] of the emitted xenon tube 45 is changed by the filter 44 to the color temperature Kb ′.
It is converted to a color temperature Kb [K] higher than [K].

As can be seen by comparing FIGS. 30 and 31,
Even when the control target ranges of the combined color temperatures are the same range G, if the filters used have different color temperature conversion abilities, the amount of deviation from the control target color temperature Kd is different. For example, when the light emission amount of the xenon tube 41 becomes 増 え P and becomes Pa ′ and the light emission amount of the xenon tube 45 becomes △ P and becomes Pb ′, the composite color temperature of the two xenon tubes 41 and 45 becomes Kd ′. Become. On the other hand, the amount of light emitted from the xenon tube 41 decreases by
a ”, and the amount of light emitted from the xenon tube 45 increases by ΔP and becomes P
When it becomes b ", the combined emission color temperature becomes Kd". Therefore, the deviation range Kd ″ −K from the target color temperature Kd [K]
d ′ is the range e1 in FIG. 30 and the range e2 in FIG. 31. As is clear from the drawing, the error in the method of FIG. 31 increases when e1 <e2.

Therefore, the control target value of the color temperature is in the range G
When (Ka ′ ≦ G ≦ Kb ′), it is most ideal to use the color temperature conversion filter 40 satisfying the expression (6) and the color temperature conversion filter 44 satisfying the expression (7). Upper limit color temperature Kb '[K] and lower limit color temperature Ka'
[K] changes depending on the environment in which shooting is performed using the flash device 25. For example, when it is desired to cover a wide range of shooting environments from a shooting environment with natural light to a shooting environment with a candle, the upper limit color temperature Kb ′ of the control target range G is about 10,000 [K], and the lower limit color temperature Ka ′ is About 100
0 [K].

With respect to the above range G, the xenon tubes 41, 4
If the primary color temperature Kc is about 6000 [K], the color temperature conversion capability Ta of the color temperature conversion filter 40 is about 833.
3 [Mired], the color temperature converting capability Tb of the color temperature converting filter 44 becomes about -66.7 [Mired]. By adjusting the amount of light emitted from the xenon tubes 41 and 45 using the color temperature conversion filters 40 and 44 having such color temperature conversion capabilities Ta and Tb, the combined color temperature KBS of the strobe light emitted from the strobe device 25 is obtained. It becomes possible to approximate the color temperature KB of the ambient light.

The operation of the second embodiment will be described. FIG. 32 is a sequence diagram showing an outline of the photographing process in the second embodiment. When the release switch 33 is half-pressed by the photographer (step D20), the luminance of the subject 35 is measured using the photometric sensor 30 and the photometric circuit 31. Exposure calculation processing is performed in the exposure calculation circuit 32 in accordance with the measured luminance value of the subject 35 (step D).
21).

In the exposure calculation processing, the operation time of the electronic shutter of the CCD 11, the necessity of light emission of the strobe device 25, and the like are determined. The charging of the main capacitors C3 and C4 by the charging circuit 50 is performed when a main switch of the still video camera to which the present embodiment is applied is turned on or a switch (not shown) for instructing to perform strobe shooting is operated. It is performed at the point of time. Also, the charging process is started at the end of the shooting with flash emission in step D30 described later. This charging process will be described later.

When the release switch 33 is fully pressed from the half-pressed state after the photometry and exposure calculation processing is completed (step D22), the color temperature of the light F4 coming from the subject 35 is measured using the colorimetric sensor 23. It is determined by the color control circuit 24 (step D23). The light F4 is light from a light source around the subject 35. By adjusting the amount of light emitted from each of the xenon tubes 41 and 45 according to the color temperature of the light F4, the combined color temperature of the entire flash device 25 can be reduced. Adjustment, resulting in a more natural still photography.

From the measured color temperature, the white balance adjustment circuit 14 determines the color difference signal (R−R) based on the color temperature.
The amplification degree for each of Y) ₀ and (B−Y) ₀ is adjusted, and white balance adjustment is performed (step D2).
4). Then, based on the photometric value, the opening amount of the aperture 20 provided in front of the CCD 11 is controlled by the system control circuit 22, and the amount of light F4 from the subject 35 incident on the CCD 11 is adjusted (step D25). Further, the charge accumulation time of the photoelectric conversion signal in the CCD 11, that is, the electronic shutter time is determined from the photometry result, and the charge accumulation is started (step D26).

The accumulation of the signal charges in step D26 is started, and if the strobe light is required by the strobe device 25 based on the determination of the photometry result, the strobe light emission control described later is started (step D2).
7). When photographing with flash emission is completed, a shift pulse is input from the image sensor driving circuit 26 to the CCD 11 under the control of the system control circuit 22. With this shift pulse, the charge accumulation of the CCD 11 is completed (Step D28), and the aperture 20 is closed (Step D29). Thereafter, a signal charge readout control signal such as a transfer pulse is input from the image pickup device driving circuit 26 to the CCD 11, and the signal charges accumulated in the CCD 11 are supplied to the CDS circuit 12 as an image signal to remove reset noise. In the color separation circuit 13, a luminance signal Y and two color difference signals (RY) ₀ ,
(BY) ₀ is generated.

The color difference signals (RY) ₀ and (BY) ₀ are supplied to a white balance adjusting circuit 14 where the white balance is adjusted. The color difference signals (RY) and (BY) whose white balance has been adjusted are subjected to predetermined processing in the signal processing circuit 15 together with the luminance signal Y, and then output to the display device 17 via the interface circuit 16. Is displayed on the screen. These signals are supplied from the signal processing circuit 15 to the FM modulation circuit 18 and FM-modulated, and the luminance signal and the color difference signal are recorded on the recording medium M such as a magnetic disk via the recording circuit 19 (step D).
30).

The charging process of the main capacitors C3 and C4 will be described. FIG. 33 shows main capacitors C3 and C4.
2 is a flowchart illustrating a process for simultaneously charging the battery. The switch control signal S2 is supplied to the photo MOS relays 85a and 85b.
0 and S21 are simultaneously output from the system control circuit 22 (step 110). Switch control signal S2
By 0 and S21, light emitted from the light emitting diodes 82a and 82b is projected on the photoelectric elements of the switch units 84a and 84b, and the light causes a photoelectric conversion current to flow through the photoelectric elements. This photoelectric conversion current is converted into a voltage signal by a bleeder resistor and applied between the source and the gate of the power MOSFET. This turns on the power MOSFET
Then, the switch units 84a and 84b are turned on.

The terminal voltages of the main capacitors C3 and C4, that is, the potentials of the signal lines S12 and S18 are changed by turning on the switch portions 84a and 84b.
It becomes equal to the potential of the signal line S19. The potential of the signal line S19 is proportional to the potential of the connection midpoint P1. The potential at the connection midpoint P1 is converted by the A / D converter 56 and monitored by the system control circuit 22. That is, the charging voltage of the main capacitor C3 or the main capacitor C4 is indirectly monitored by the system control circuit 22. Then, the system control circuit 22 determines whether the charging voltage of the main capacitors C3 and C4 is equal to or higher than the charging stop voltage (step 11).
1).

If the charging voltage of the main capacitors C3 and C4 is higher than the charging stop voltage, the switch control signal S2
0, the output of S21 is stopped (step 115), and FIG.
The simultaneous charging process shown in FIG. Here, the charging stop voltage means a voltage at which light emission of the xenon tube 41 or the xenon tube 45 can be started or a voltage (corresponding to a guide number of a strobe device) at which a sufficient amount of light can be obtained by strobe light emission. Main capacitors C3, C4
If the charging voltage is not higher than the charging stop voltage, the charging start signal S2 is sent to the charging circuit 50 by the system control circuit 2.
2 (step 112).

The charge start signal S2 causes the charge circuit 5
From 0, a charging current is supplied to the main capacitors C3 and C4 via the diode D1 and the switch units 84a and 84b. As a result, electric charges are sequentially accumulated in the main capacitors C3 and C4. Then, the charging is continued using the A / D converter 56 until the charging voltage of the main capacitors C3 and C4 becomes equal to or higher than the charging stop voltage (step 11).
3). When the charging voltage of the main capacitors C3 and C4 becomes equal to or higher than the charging stop voltage (Ye is determined in step 113).
s), the output of the charge start signal S2 is stopped (step 1).
14) Further, the output of the switch control signals S20 and S21 is stopped (step 115), and the simultaneous charging process ends.

FIGS. 34 and 35 show main capacitors C3 and C3.
4 shows a flowchart in which the charging of No. 4 is performed separately. FIG.
In 4, the switch control signal S20 is first output from the system control circuit 22 to the photo MOS relay 85a (step 116). As a result, the switch portion 84a is turned on. Then, the system control circuit 22 determines whether or not the charging voltage of the main capacitor C4 is equal to or higher than the charging stop voltage by using the A / D converter 56 (step 117). If the charging voltage is equal to or higher than the charging stop voltage, the output of the switch control signal S20 is stopped (step 121), and the charging process of the main capacitor C3 shown in FIG. 35 is started. However, if the charging voltage of the main capacitor C4 is not higher than the charging stop voltage, the charging start signal S2 is output from the system control circuit 22 to the charging circuit 50 (step 118).

Since the switch 84a is ON,
The charging from the charging circuit 50 to the main capacitor C4 is started by the charging start signal S2. Then, the charging is continued until the charging voltage of the main capacitor C4 becomes equal to or higher than the charging stop voltage (step 119). When the charging voltage of the main capacitor C4 becomes equal to or higher than the charging stop voltage (Yes in the determination at Step 119), the output of the charging start signal S2 is stopped (Step 120), and the switch control signal S
20 is stopped (step 121).

The charging process of the main capacitor C3 will be described. In FIG. 35, first, a switch control signal S21 is output from the system control circuit 22 to the photo MOS relay 85b (step 124). By the switch control signal S21, only the switch section 84b is turned on. Then, the system control circuit 22 determines whether or not the charging voltage of the main capacitor C3 is equal to or higher than the charging stop voltage (step 126). If the charging voltage is higher than the charging stop voltage,
The output of the switch control signal S21 is stopped (step 1).
34), the process of sequentially charging the main capacitors C3 and C4 ends. However, if the charging voltage of the main capacitor C3 is not higher than the charging stop voltage, the charging start signal S2 is input to the charging circuit 50 from the system control circuit 22 (step 128).

When the charging start signal S2 is input, charging of the main capacitor C3 from the charging circuit 50 is started.
Then, the charging is continued until the charging voltage of the main capacitor C3 becomes equal to or higher than the charging stop voltage (step 13).
0). If the charging voltage of the main capacitor C3 becomes equal to or higher than the charging stop voltage due to charging (Yes in the determination at Step 130), the output of the charging start signal S2 is stopped (Step 132), and the output of the switch control signal S21 is further stopped. (Step 134).

The flash light emission control will be described. FIG.
6 and 37 show flowcharts of strobe light emission control in this embodiment. In FIG. 36, the system control circuit 22 calculates the ratio A: B of the light emission amounts of the xenon tubes 41 and 45 so as to match the measured value of the color temperature of the light F4 from the subject 35. This light emission ratio A: B
Is determined according to the control target value of the composite color temperature of the strobe device 25. For example, when the composite color temperature is lowered, the color temperature is increased by the filter 44 as shown in FIG. The light emission amount of the xenon tube 45 is reduced, and the light emission amount of the xenon tube 41 whose color temperature is lowered by the filter 41 is increased.

A xenon tube for emitting light (hereinafter referred to as a xenon tube 4
5 will be described first) is obtained from the data table stored in the memory of the system control circuit 22 so that the emission color temperature becomes substantially equal to the measured color temperature. The maximum light emission time La is a time limit at which the xenon tubes 41 and 45 can maintain the above light emission amount ratio A: B when the xenon tubes 41 and 45 emit light by sufficiently using the charges of the main capacitors C3 and C4, respectively. Means. That is, if the xenon tube 45 emits light continuously for the maximum light emission time La or longer, even if the xenon tube 41 emits light using all the electric charges of the main capacitor C3, the limit value cannot maintain the ratio A: B.

The data of the maximum light emission time La is the signal line S
The time is set in the timer circuit 34 via the timer 15 and the timer operation is started (step 136). When the measurement time exceeds the maximum light emission time La, the timer circuit 34 outputs a time-over signal S14 to the system control circuit 22. Also, the amount of light emitted from a xenon tube is generally not simply proportional to the light emission time. Further, the amount of reflected light also changes depending on the reflectance of the subject. Therefore, dimming control is applied to the xenon tube that emits light. This dimming control means that, for the purpose of obtaining a good photographed image, a strobe light emitted from the strobe device 25 toward the subject 35 is used to control the xenon tube so that the amount of reflected light from the subject 35 reaches a predetermined amount. This is to adjust the amount of light emission.

Therefore, the still video camera 3
In the case where the distance to 5 is long and the amount of strobe light reflected from the subject 35 is small, it is necessary to make each xenon tube emit light longer. In other words, depending on the shooting conditions, the dimming control is performed, so that the amount of light emitted from the xenon tube that emits light first may increase.

If the amount of light emitted from the xenon tube that emits light first increases, the ratio A: B may not be maintained even if the xenon tube that emits light later emits full light, as described above. If the ratio A: B cannot be maintained, the combined color temperature of the strobe device 25 cannot be adjusted to the target value, and the object of the present invention for obtaining a more natural captured image by controlling the color temperature of the strobe light is impaired. . Therefore, in order to prevent the light emission amount of the xenon tube 45 from becoming too large by the light control, the light control is limited by the above-described maximum light emission time La.

In order to perform dimming control, an appropriate integral value Ma (digital data) corresponding to the xenon tube 45 is supplied from the system control circuit 22 to the D / A of the flash dimming circuit 29.
The data is output to the converter 62 (step 137). This proper integration value Ma is a value corresponding to the ratio A of the xenon tube 45, and is obtained from the measured color temperature of the light F4 using the data table stored in the memory of the system control circuit 22. The proper integration value Ma input to the D / A converter 62 is converted into an analog signal S8 and output to the comparator 61.

Next, the integration start signal S5 is output from the system control circuit 22 to the reset switch 66 of the strobe light control circuit 29, and the integration circuit composed of the operational amplifier 60, the integration capacitor 64 and the reset switch 66 is reset (step S1). 138). After resetting the switch 66, integration is started (step 139). As a result, the photocurrent of the photometric sensor 28 is integrated over time by the operational amplifier 60. That is, the photocurrent flowing through the photometric sensor 28 changes according to the illuminance of the reflected light F4 from the subject 35 received by the photometric sensor 28. By integrating this photocurrent, the reflected light F4 An accumulated light amount is detected. Then, the comparator 61 compares the magnitude of the integral value with the appropriate integral value Ma.

Along with the start of the integration, a light emission trigger signal S3 is output from the system control circuit 22 to the IGBT 53 (step 140). This light emission trigger signal S3
Turns on, the IGBT 53 is turned on, and the electric charge stored in the trigger capacitor C2 flows to the signal line S10 via the IGBT 53. The discharge of the trigger capacitor C2 causes a current to flow through the low voltage side coil of the trigger transformer T2, and induces a high voltage trigger signal through the high voltage side coil.
This trigger signal is applied to the trigger electrode of the xenon tube 45, and the xenon gas in the xenon tube 45 is ionized. Due to the ionization of the xenon gas, the resistance between the anode terminal and the cathode terminal sharply decreases, a spark current flows from the anode terminal to the cathode terminal, and a flash is generated.

The reflected light F4 arriving from the subject 35 increases due to the strobe light F3, and when the output value from the operational amplifier 60 reaches the proper integral value Ma, the quench signal S6
Is input to the system control circuit 22. The presence or absence of the quench signal S6 is monitored by the system control circuit 22 (step 141), and when the quench signal S6 is input, the output of the light emission trigger signal S3 is stopped (step 143).

The emission trigger signal S3 is stopped and the IGBT
When the switch 53 is turned off, the current flowing through the xenon tube 45 is cut off by the IGBT 53, and the flash emission of the xenon tube 45 is stopped. However, when the quench signal S6 is not input, whether or not the time-over signal S14 from the timer circuit 34 is input is determined by the system control circuit 22.
Is determined (step 142). If the time-over signal S14 has not been input, the process returns to step 141, and it is determined again whether or not the quench signal S6 has been input. Conversely, when the time-over signal S14 is input, the output of the light emission trigger signal S4 is stopped, and the light emission of the xenon tube 45 is stopped (step 143). When the output of the light emission trigger signal S3 is stopped in Step 143, the timer circuit 34 is stopped and reset (Step 14).
4) The start of emission of the next xenon tube 41 is controlled.

In FIG. 37, as in step 136, the maximum light emission time Lb
Is obtained from the data table based on the measured color temperature of the light F4 from the subject 35. This maximum light emission time Lb
Is set in the timer circuit 34, and the timer circuit 34 starts counting time (step 145). Further, in order to perform dimming control of the xenon tube 45, an appropriate integration corresponding to the ratio B of the xenon tube 41 is performed using a data table stored in the memory of the system control circuit 22 based on the measured color temperature of the light F4. A value Mb (digital data) is obtained and output to the D / A converter 62 (step 14).
6). Appropriate integral value Mb set in D / A converter 62
Is converted to an analog signal S8 and output to the comparator 61. This proper integration value Mb is equal to the proper integration value M
As in the case of a, this is a threshold value for maintaining the ratio A: B and judging that the amount of reflected light from the subject 35 has reached an amount at which an optimal image can be obtained.

Then, the integration circuit of the operational amplifier 60 is reset by the integration start signal S5 (step 14).
7), the integration by the operational amplifier 60 is started (step 148). Thereafter, the light emission trigger signal S4 changes to the IGBT5
2 and the light emission of the xenon tube 41 is started (step 149). When the quench signal S6 is input from the comparator 61 or the time-over signal S14 is input from the timer circuit 34, the output of the light emission trigger signal S4 is stopped, and the light emission of the xenon tube 41 is stopped ( Steps 174 to 176). When light emission is stopped, the timer circuit 34 stops counting time (step 177). Thereafter, depending on the conditions, the charging process in FIGS. 33 to 35 is started for the next new strobe light emission control.

As described above, according to the present embodiment, a xenon tube including a plurality of filters 40 and 41 having different emission color temperatures is used to control the combined color temperature of light emitted from the strobe device 25. In addition, each of the plurality of xenon tubes is provided with an independent capacitor for accumulating the light-emitting charge. However, in response to the increase in the number of capacitors, the charging circuit 50 as charging means is integrated into one, and the selection of the capacitors C3 and C4 for charging is performed by the photo MO.
This is performed by the S relays 85a and 85b. As a result, sufficient charges can be accumulated in the capacitors C3 and C4, and the amount of light emitted from each xenon tube can be prevented from becoming insufficient. Therefore, the combined color temperature of the strobe device 25 can be controlled more accurately. In addition, since the charging circuits 50 are integrated into one, it is possible to prevent the entire flash device 25 from increasing in size. In addition, the main capacitors C3, C
After the charging of the switch 4 is completed, the switches 84a and 84b are turned off, so that electric charges are discharged from the main capacitors C3 and C4 to the ground common signal line S10 via the resistors R1 and R2 or the charging circuit 50. Can be prevented, and unnecessary consumption of the electric charges of the main capacitors C3 and C4 can be prevented.

In this embodiment, the photo MO
Instead of the S relays 85a and 85b, a mechanical relay that opens and closes a secondary switch with magnetic energy, a photo coupler, or the like may be used. Further, in the present embodiment, the xenon tube 45 in which the strobe light is converted to a high color temperature is emitted before the xenon tube 41,
The xenon tube 41 in which the color temperature of the strobe light is converted to a relatively low temperature may be emitted first.

FIG. 38 shows a third embodiment of a strobe device 25 according to the present invention. In this figure, the same circuits as those of the first and second embodiments are denoted by the same reference numerals. In the third embodiment, the diodes D2 and D3 are connected between the signal line S19 and the signal lines S18 and S12, respectively, and the charging current output from the charging circuit 50 is applied to the diodes D2 and D3. Through each main capacitor C
3, supplied to C4. The diodes D2 and D3 prevent the accumulated charges of the main capacitors C3 and C4 from flowing into the other capacitor and from flowing back to the charging circuit 50.

The signal line S18 and the ground common signal line S10
, Resistors R12 and R13 are connected in series, and the connection point P2 between the resistors R12 and R13 is A /
The potential at the connection point P2 is A / D-converted and input to the system control circuit 22 as a signal S17. Also, the main capacitor C
Resistors R8 and R9 are connected in series to both ends of 4 and a connection point P1 between the resistors R8 and R9 is connected to the A / D converter 56. The potential of the connection point P1 is A / D converted by the A / D converter 56 and input to the system control circuit 22 as a signal S16. That is, the A / D converter 56 is used to monitor the charging voltage of the main capacitor C4, and the A / D converter 51 is used to monitor the charging voltage of the main capacitor C3. Other configurations are substantially the same as those of the second embodiment.

The operation of the third embodiment will be described. Note that still video shooting and light emission control of the strobe device 25 are as follows.
The description is omitted because it is the same as the second embodiment. FIG.
The main capacitors C3, C3 in the third embodiment
4 shows a flowchart of a charging process 4. In this figure, the voltage of the signal line S12, that is, the main capacitor C4
Is monitored by the system control circuit 22 using the A / D converter 56, and if the charging voltage of the main capacitor C4 is not equal to or higher than the charging stop voltage (No in step 300), the charging circuit 50 Charge start signal S2 is input from system control circuit 22 (step 302).

If the charge voltage of the main capacitor C4 is equal to or higher than the charge stop voltage (meaning the potential difference between both ends of the capacitor when the electric charge necessary for the light emission of the xenon tube 45 is accumulated in the main capacitor C4) (Yes in step 300)
s) Then, the potential of the signal line S18 is measured using the A / D converter 51, and the charging voltage of the main capacitor C3 is indirectly checked (step 301). That is, if the charging voltage of the main capacitor C3 is smaller than the charging stop voltage (No in the determination of step 301), the charging start signal S2
Is output from the system control circuit 22 to the charging circuit 50 (step 302). Conversely, if the charging voltage of the main capacitor C3 is equal to or higher than the charging stop voltage, no charging process is performed, and the charging process of FIG. 39 ends.

After the charging of the capacitor C4 or C3 is started by outputting the charging start signal S2 (step 302), it is determined whether or not the charging voltage of the main capacitor C4 is higher than the charging stop voltage (step 302). Step 30
3). If the charging voltage of the main capacitor C4 is equal to or higher than the charging stop voltage (Yes in Step 303), it is determined whether the charging voltage of the main capacitor C3 is equal to or higher than the charging stop voltage (Step 304). When it is determined in step 304 that the charging voltage of the main capacitor C3 has become equal to or higher than the charging stop voltage, the output of the charging start signal S2 is stopped (step 305).

As described above, in the third embodiment, in order to adjust the combined color temperature of the strobe device 25, a plurality of xenon tubes for converting strobe light into different color temperatures are used. Provided an independent capacitor. However, in response to this increase in the number of capacitors, the number of charging means is reduced by using only one charging circuit 50 as charging means. In addition, the charging voltages of the main capacitors C3 and C4 are checked by the A / D converters 51 and 56.
Thus, it is possible to prevent the amount of light emitted from each xenon tube from being insufficient due to insufficient charging of the capacitor. As a result, the combined color temperature of the strobe device 25 can be accurately controlled, and the size of the strobe device can be prevented from increasing.

Further, by converting the color temperature of light emitted from the xenon tube using a color temperature conversion filter and adjusting the amount of light emitted from each xenon tube, various light emitting means, that is, various color temperatures of the xenon tube can be obtained. Light of a synthetic color temperature can be generated. Therefore, light having a color temperature corresponding to general natural light or artificial light such as a fluorescent light can be generated, and a photographed image with more excellent white balance can be obtained in any photographing environment.

Although two types of color temperature conversion filters are used in the second and third embodiments, three or more types of color temperature conversion filters may be used simultaneously. For example, when three or more types of color temperature conversion filters are used, a xenon tube dedicated to each filter is provided, and the amount of light emitted from each xenon tube is determined and controlled from the color temperature of the light F4. In addition, the number of main capacitors is increased in each embodiment,
In the embodiment, the number of photo MOS relays 85 is increased, and in the second embodiment, the number of A / D converters and diodes is increased. Thus, the combined color temperature of the strobe device 25 can be controlled more finely. When a plurality of color temperature conversion filters are provided, one of the color temperature conversion filters may lower the color temperature and the other color temperature conversion filter may increase the color temperature.

The A / D converters 51 and 56 of the above embodiments.
As for the method of use, the charging voltage of the main capacitor is divided by a plurality of resistors and indirectly measured, but the charging voltage of the main capacitor can be directly A / D converted (output from the charging circuit 50). If the input withstand voltage for the pulsed charging signal is high), the resistors R8, R
9, R12, and R13 may be omitted, or the charge stop voltage may be input to the D / A converter as a threshold, and the analog signal of the threshold and the potential difference between both ends of the capacitor may be compared by an analog comparator. May be monitored.

In the second and third embodiments, the IGBTs 52 and 53 are used as the switch means for controlling the emission and stop of each xenon tube. However, this may be performed by using a plurality of thyristors. Well, it is not particularly limited to IGBT. The means for measuring the strobe reflected light from the subject 35 and the means for generating the quench signal are not limited to the operational amplifier and the analog comparator as shown in FIG. 3, and the digital circuit may constitute an integrating circuit and a comparing circuit. Good. Further, a xenon tube is used as a light source as a light emitting means in the first, second, and third embodiments. However, the present invention is not limited to this.
Any device can be used as long as it can repeatedly generate and stop the flash by the FF.

In the second and third embodiments,
The reflected light from the subject to be incident on the photometric sensor 28 and the colorimetric sensor 23 may use a part of the light passing through a photographic lens system provided in the CCD 11. With such a configuration, the amount of light incident on the CCD 11 can be measured more accurately, and more accurate dimming control and color temperature control can be performed. Furthermore, in each of the above embodiments, the still video camera has been described. However, the present invention can be applied to a strobe device including the strobe device 25, the colorimetric sensor 23, the photometric sensor 28, and the like. That is, CCD1
1. The present invention may be applied only to a strobe device without a still video photographing circuit such as the signal processing circuit 15 and the recording circuit 19, and if such a strobe device is used in a conventional still camera or the like, A more natural image can be obtained during shooting.

FIG. 40 shows a fourth embodiment of a strobe device 25 according to the present invention. The configuration of the entire still video camera is the same as that of the second embodiment shown in FIG. FIG.
The strobe device 25 connected to the system control circuit 22 includes a xenon tube 41 having a color temperature conversion filter 40 for changing the color temperature of strobe light to a lower direction.
And a xenon tube 45 for projecting strobe light toward the subject 35 as it is. Xenon tube 41,
Each cathode terminal 45 is connected to the collector terminal of the IGBT 52. The emitter terminal of the IGBT 52 is connected to the common ground signal line S10, and the base terminal is connected to the system control circuit 22, and the light emission trigger signal S3 is input from the system control circuit 22 to the base terminal. The signal line S10 is connected to the charging circuit 5
0 is connected.

The anode terminals of the xenon tubes 41 and 45 are connected to the charging signal output terminal of the charging circuit 50 by a signal line S12. Signal line S12 and common ground signal line S10
Is connected between the trigger circuit 54 and the main capacitor C3, and the charge for flashing of the xenon tubes 41 and 45 is stored in the main capacitor C3 by the charging current output from the charging circuit 50 to the signal line S12. That is,
Unlike the second and third embodiments, the xenon tubes 41, 45
Are stored in one main capacitor C3. The start of charge accumulation of the main capacitor C3, that is, the start of charging, is performed by a charging start signal S2 input from the system control circuit 22 to the charging circuit 50, and the end is determined by a charging signal S1 output from the charging circuit 50. Will be

The configuration of the trigger circuit 54 for generating flash light of the xenon tubes 41 and 45 will be described. Trigger circuit 54
Is composed of a resistor R5, a trigger capacitor C1, and a trigger transformer T1. One end of the resistor R5 is connected to the signal line S12, and the other end is connected to one end of the trigger capacitor C1 and the collector terminal of the IGBT 52. The other end of the trigger capacitor C1 is connected to the low voltage side coil of the trigger transformer T1, and the common terminal 76 of the trigger transformer T1 is connected to the common ground signal line S10.

The high voltage side coil of the trigger transformer T1 is connected to each of the switch sections 7 built in the photoMOS relays 72 and 75.
1, 74 are connected to one end. The other end of the switch 74 is connected to the trigger electrode of the xenon tube 45, and the other end of the switch 71 is connected to the trigger electrode of the xenon tube 45. The switch units 71 and 74 are composed of a photoelectric element, a bleeder resistor, a power MOSFET, and the like.

The anode terminal of the light emitting diode 73 provided in the photo MOS relay 75 is connected to the system control circuit 22 via the resistor R21, and the trigger select S20 is input from the system control circuit 22. Similarly, the anode terminal of the light emitting diode 70 included in the photo MOS relay 72 is connected to the resistor R20.
Is connected to the system control circuit 22 via the control circuit 22, and a trigger select S21 is input from the system control circuit 22. The cathode terminals of the light emitting diodes 70 and 73 are connected to the common ground signal line S10. Further, time measurement data is input to a timer circuit 34 connected to the system control circuit 22 via a signal line S15. Then, a time-over signal S14 based on the time measurement result is input from the timer circuit 34 to the system control circuit 22.

The operation of the present embodiment will be described. The outline (shown in FIG. 32) of the photographing process in the fourth embodiment is the same as that in the second embodiment. The charging of the main capacitor C3 by the charging circuit 50 is performed when a main switch of the still video camera to which the present embodiment is applied is turned on or a switch (not shown) for instructing to perform strobe shooting is operated. Alternatively, it is performed after the completion of the flash emission photographing described later.

The charging process for the main capacitor C3 will be briefly described. When the charging start signal S2 is input from the control circuit 22 to the charging circuit 50, a pulsed charging signal obtained by increasing the power supply voltage of a battery or the like provided in the still video camera is supplied from the charging circuit 50 via the signal line S12. It is input to the main capacitor C3. As a result, charges are gradually accumulated in the main capacitor C3, and the voltage of the signal line S12 is increased by the accumulated charges. The rising voltage of the signal line S12 is monitored by the charging circuit 50, and when the voltage exceeds the charging stop voltage, the charging circuit 50
, The charge completion signal S1 is input to the control circuit 22. The charge stop voltage here is a xenon tube 41,
45 is a voltage at which light emission can be started or a voltage (corresponding to a guide number of a strobe device) at which a sufficient amount of light can be obtained by strobe light emission.

The flash emission control will be described. FIG.
1 and 42 show flowcharts of strobe light emission control in this embodiment. This flowchart is basically the second
This is the same as the embodiment. In FIG. 41, the xenon tubes 45 and 4 are adjusted to match the measured color temperature value of the light F4.
The ratio A: B of the light emission amount of 1 is the system control circuit
2. The ratio A: B is determined according to the control target value of the combined emission color temperature of the strobe device 25. For example, when controlling to a higher color temperature,
The light emission amount of the xenon tube 45 having a high color temperature is increased, and the light emission amount of the xenon tube 41 having a low color temperature is reduced. In addition, according to the determined ratio A: B, control is performed so that the xenon tube having a small light emission amount emits light first.

In determining the light emission order, if the xenon tube emitting a large amount of light is made to emit light first, a large amount of light is emitted, so that a large amount of electric charge in the main capacitor C3 is consumed. As a result,
Since there is a possibility that a voltage required for generating flash light may not be applied to the xenon tube to be illuminated next, the xenon tube having a small light emission amount is illuminated first in order to prevent this.

When the ratio A: B of the light emission amounts is, for example, A <B, the xenon tube 45 emits light first. Along with the determination of the xenon tube to be illuminated first, the maximum emission time La of the xenon tube to be illuminated (hereinafter, the case where the xenon tube 45 is illuminated first) is determined from the data table stored in the memory of the system control circuit 22. It is determined based on the measured color temperature.

First, the data of the maximum light emission time La is the signal S1.
5, the timer circuit 34 is set, and the timer circuit 34 starts a timekeeping operation (step 240). Next, in order to perform dimming control, an appropriate integral value Ma (digital data) corresponding to the xenon tube 45 is supplied from the system control circuit 22 to the D / A converter 6 of the strobe dimming circuit 29.
2 (step 241, see FIG. 3). This proper integration value Ma is a value corresponding to the ratio A of the xenon tube 45, and is obtained from the measured color temperature of the light F4 using the data table stored in the memory of the system control circuit 22. This proper integration value Ma is determined by the subject 35
Represents a threshold value at which a proper exposure can be obtained with the light F4 from the camera.
The proper integration value Ma input to the D / A converter 62 is converted into an analog voltage signal S8 and input to the comparator 61.

Then, an integration start signal S5 is output from the system control circuit 22 to the switch 66, the integration circuit is reset, and thereafter integration is started (steps 242, 243). As a result, the light current of the photometric sensor 28 is integrated over time. That is, according to the illuminance of the reflected light F4 from the subject 35 received by the photometric sensor 28,
The photocurrent flowing through the photometric sensor 28 changes. By integrating this photocurrent, the accumulated light amount of the reflected light F4 from the subject 35 is detected. Then, the comparator 61 compares the magnitude of the integral value of the integrating circuit composed of the operational amplifier 60 and the like with the appropriate integral value Ma.

On the other hand, along with the start of the integration, the trigger select S20 is output from the system control circuit 22 to the light emitting diode 73 of the photo MOS relay 75 (step 244). Note that the trigger select S20 and the trigger select S21 are exclusively output from the system control 22 to the relays 72 and 75. Trigger select S2
Since the light of the light emitting diode 73 generated by 0 is projected on the photoelectric element of the switch unit 74, a photoelectric conversion current flows through the photoelectric element. This photoelectric conversion current is converted into a voltage signal by a bleeder resistor and applied between the source and the gate of the power MOSFET. Thereby, power MOSFE
T is turned on, and the switch unit 74 is turned on. That is, the switch section 74 is turned on by the trigger select S20.

This is because the switch 74 is turned ON only when the xenon tube 45 emits light. After this,
The light emission trigger signal S3 is output from the system control circuit 22 to the IGBT 52 (step 245). By the input of the light emission trigger signal S3, the IGBT 52
N, and the electric charge stored in the trigger capacitor C1 of the trigger circuit 54 flows out to the common ground signal line S10 via the IGBT 52.

A current flows through the low voltage side coil of the trigger transformer T1 due to the discharge of the trigger capacitor C1, and a high voltage trigger signal is induced in the high voltage side coil of the trigger transformer T1. This trigger signal is ON only in the switch section 74
As a result, the voltage is applied to the trigger electrode of the xenon tube 45. When the trigger signal is applied, the xenon gas in the xenon tube 45 is ionized. Due to the ionization of the xenon gas, the resistance between the anode terminal and the cathode terminal sharply decreases, a spark current flows from the anode terminal to the cathode terminal, and strobe light F3 is generated. The reflected light F4 arriving from the subject 35 increases due to the strobe light F3, and when the integrated value of the integrating circuit including the operational amplifier 60 reaches the proper integrated value Ma, the quench signal S6 is sent from the comparator 61 to the system control circuit 22. Is entered. The presence or absence of the input of the quench signal S6 is identified in the system control circuit 22 (step 246), and when the quench signal S6 is input, the output of the light emission trigger signal S3 is stopped (step 248).

When the output of the light emission trigger signal S3 is stopped, the IGB
T52 is turned off, and the current flowing through the xenon tube 45 is cut off. Thus, the flash emission of the xenon tube 45 is stopped. However, when the quench signal S6 has not been input (No in the determination of step 246), the timer circuit 34
The system control circuit 22 determines whether or not the time-over signal S14 has been input (step 24).
7). If the time-over signal S14 has not been input, the process returns to step 246, and it is determined again whether or not the quench signal S6 has been input. Conversely, when the time-over signal S14 is input, the output of the light emission trigger signal S3 is stopped, and the light emission of the xenon tube 45 is stopped (step 248).

When the output of the light emission trigger signal S3 is stopped, the output of the trigger select S20 is stopped, and the trigger circuit 54 is disconnected from the trigger electrode of the xenon tube 45 (step 249). Then, the timer circuit 34 is stopped (Step 250), and the start of emission of the next xenon tube 41 is controlled.

The second xenon tube light emission control will be described. In FIG. 42, the maximum light emission time Lb for the xenon tube 41 is equal to the light F
4 is obtained from the data table in the system control circuit 22 based on the measured color temperature. The maximum light emission time Lb is set in the timer circuit 34, and the timer circuit 34 starts counting time (step 251).
To control the dimming of the xenon tube 41, the xenon tube 41 is used based on the measured color temperature of the light F4 using a data table stored in the memory of the system control circuit 22.
Integration value Mb (digital data) corresponding to the ratio B of
Is obtained and output to the D / A converter 62 (step 252). Appropriate integral value M input to D / A converter 62
b is converted into an analog voltage signal S8 and output to the comparator 61.

This proper integration value Mb is obtained by calculating the proper integration value M
As in the case of a, this is a threshold for maintaining the ratio A: B and identifying that the amount of reflected light from the subject 35 has reached an amount at which an optimum image can be obtained. Then, after the integration circuit is reset by the integration start signal S5, integration is started (steps 253, 254). Thereafter, the trigger select S21 is applied to the light emitting diode 70 of the photo MOS relay 72.
Is output from the system control circuit 22 (step 255). By the trigger select S21, the power MOSFET of the photo MOS relay 72 is turned on, and the switch unit 71 is turned on. Thereafter, the light emission trigger signal S3 is output to the IGBT 52, and light emission of the xenon tube 41 is started (step 256).

When the quench signal S6 is input from the comparator 61 of the strobe light control circuit 29 or the time-over signal S14 is input from the timer circuit 34, the output of the light emission trigger signal S3 is stopped, and the xenon tube is stopped. The light emission of 41 is stopped (step 259). That is, the light emission of the xenon tube 41 is continued until either the quench signal S6 for dimming control or the time-over signal S14, which is a time limit, is input to the system control circuit 22. When the light emission of the xenon tube 41 is stopped, the trigger select S21 is stopped and the xenon tube 4 is stopped.
The first trigger electrode and the trigger circuit 54 are cut off (step 260). Further, the timer operation of the timer circuit 34 is stopped (step 261).

The flow charts in FIGS. 41 and 42 are for the case where A <B in the light emission ratio A: B, and A> B.
In the case of B, the trigger select of steps 244 and 249 is changed to S21, and the trigger select of steps 255 and 260 is changed to S20.

Then, the image signal is read from the CCD 11, stored in the recording medium M, and the photographing process is completed.
Thereafter, depending on the conditions, the charging process of the main capacitor C3 is started for the next new strobe light emission control.

As described above, according to the present embodiment, a filter and a plurality of xenon tubes are used to control the combined emission color temperature of the strobe device 25, but the xenon tubes 45 and 41 are used.
Is controlled by the IGBT 52, and the connection / cutoff between the trigger electrodes of the xenon tubes 41 and 45 and the trigger circuit 54 is performed by the photoMOS relays 72 and 75. As a result, despite increasing the number of xenon tubes,
The number of accessory parts can be minimized, and the size of the strobe device can be prevented from increasing.

FIG. 43 shows a fifth embodiment of the present invention. In this figure, the same reference numerals are given to the same circuits as in the fourth embodiment. In the fifth embodiment, the application of the trigger signal generated by the trigger circuit 54 to the xenon tubes 41 and 45 is selected by the FETs 48a and 48b.
That is, the high voltage side coil of the trigger transformer T1 is connected to the drain terminal of the FET 48a via the resistor R23 and to the drain terminal of the FET 48a via the resistor R22. The source terminals of the FETs 48a and 48b are connected to the common ground signal line S10, and the respective gate terminals are connected to the system control circuit 22. FE
The trigger select S20 is input from the system control circuit 22 to T48b, and the trigger select S21 is input to the FET 48a. The overall configuration of the still video camera is the same as that of the second embodiment shown in FIG.

The operation of the fifth embodiment will be briefly described.
Still photography and strobe light emission control of the fifth embodiment are basically the same as those of the fourth embodiment. That is, in response to half-pressing and full-pressing of the release switch 33, photometry / exposure calculation for the subject 35 and color temperature measurement of the light F4 are performed. The color difference signal (RY) ₀ according to the color temperature of the light F4,
By adjusting the amplification degree of (BY) ₀ , the white balance of the image signal to be captured and recorded is maintained. Further, exposure adjustment such as adjustment of an aperture and control of an electronic shutter is performed, and strobe light emission control is performed.

In the strobe light emission control, the ratio A: B of the light emission amount of the xenon tubes 45 and 41 is determined according to the color temperature of the light F4, and the light emission order is selected according to the ratio A: B.
The light emission amount is limited by the maximum light emission time, and dimming control is performed. Trigger select S20, S21 and Xenon tube 45
Alternatively, the relationship with the light emission start operation of the xenon tube 41 will be described. Normally, the trigger selects S20 and S21 are in the "L" state, and the FETs 48a and 48b are always in the OFF state.

Therefore, the high-voltage trigger signal generated by the trigger transformer T1 is in a state where it can be applied to both the xenon tubes 45 and 41. When the xenon tube 45 emits light first, the trigger select S21 in the “H” state is set to FE.
The signal is output to T48a, the FET 48a is turned on, and the trigger signal is not applied to the trigger electrode of the xenon tube 41. In this state, a light emission trigger signal S3 is output, and a trigger signal is generated in the trigger transformer T1, as in the fourth embodiment. Since the FET 48b is OFF, the trigger signal is applied only to the trigger electrode of the xenon tube 45, and the xenon tube 45 starts emitting light. The light emission stop of the xenon tube 45 is performed by the quenching signal S6 based on the dimming control or the time-over signal S based on the light emission time limit.
When 14 is input, the output of the light emission trigger signal S3 is stopped, and the IGBT 52 is turned off.

Similarly, when the xenon tube 41 starts emitting light, the trigger select S20 in the “H” state is set to the FET 48b.
And the FET 48b is turned on, and the xenon tube 4
No trigger signal is applied to 5. After that, the light emission trigger signal S3 is output to the IGBT 52,
The trigger signal generated by the trigger transformer T1 is applied to the trigger electrode of the xenon tube 41. As a result, the xenon tube 41 starts emitting light. Light emission is stopped when the quench signal S6 or the time-over signal S14 is input.
This is performed when the IGBT 52 is turned off.

As described above, in the fourth and fifth embodiments,
In order to adjust the combined emission color temperature of the strobe device 25,
Although a plurality of xenon tubes different from the filter are used, a main capacitor for storing the flash charges of the plurality of xenon tubes, a charging circuit for charging the main capacitor, a trigger circuit for generating a flash, and a The IGBTs for controlling the start and stop of light emission are each one. However, two photo MOS relays or FETs were used to selectively apply the trigger signal of the trigger circuit to each xenon tube. Since the mounting space of such a photo MOS relay or FET is extremely small, the increase in the number of components can be sufficiently suppressed despite the increase in the number of xenon tubes. As a result, an increase in the size of the strobe device can be prevented.

Furthermore, since the emission color temperature of at least one xenon tube is adjusted by a color temperature conversion filter and a plurality of xenon tubes having different emission color temperatures are used, the combined emission color temperature of the strobe device can be freely controlled. For example, since light having a color temperature corresponding to general natural light or artificial light such as a fluorescent light can be generated, more natural color reproduction of a photographed image can be realized in any photographing environment.

In the fourth and fifth embodiments, the color temperature conversion filter 40 is used only for the xenon tube 41. However, this is a conversion to a color temperature lower than the color temperature of the xenon tube, such as for indoor photography. As a matter of course, the color temperature conversion filter 44 may be used for the xenon tube 45, and three or more types of color temperature conversion filters may be used. For example, when three or more types of color temperature conversion filters are used, a xenon tube dedicated to each filter is provided, and the amount of light emitted from each xenon tube is controlled according to the color temperature of the light F4. At the same time, the number of photo MOS relays or FETs as means for selecting and applying a trigger signal to each xenon tube is increased. Thereby, the same effect as in the above embodiment can be obtained.

In the fourth and fifth embodiments, the IGBT is used as the light emission control switch means for controlling the light emission / stop of each xenon tube. However, this may be performed using a plurality of thyristors. It is not particularly limited. The means for measuring the strobe reflected light from the subject 35 and the means for generating a quench signal are not limited to the operational amplifier and the analog comparator as shown in FIG. 3, and the digital circuit may constitute an integrating circuit and a comparing circuit. . Although a xenon tube is used as a light source as a light emitting unit in each embodiment, the light source is not limited to this.
Any light emitting means that can repeatedly generate and stop the flash by turning on and off the current may be used.

In each embodiment, the photometric sensor 2
8. As the reflected light from the subject to be incident on the colorimetric sensor 23, a part of the light passing through the photographing lens system provided in the CCD 11 may be used. By doing this,
The amount of light incident on the CCD 11 can be measured more accurately, and more accurate dimming control and strobe light color temperature control can be performed. Photo M in Fourth and Fifth Embodiments
Instead of the OS relay or the FET, a mechanical relay or a photo coupler that opens and closes the secondary side switch by magnetic energy or a general bipolar transistor may be used, and any selection can be made as long as the conductive state can be turned ON / OFF. Means may be used.

In the fourth and fifth embodiments, still video cameras have been described. However, the present invention can be applied to a strobe device including a strobe device 25, a colorimetric sensor 23, a photometric sensor 28, and the like. That is, if the present invention is applied to a strobe device without a still video photographing circuit such as the CCD 11, the signal processing circuit 15, and the recording circuit 19, it can be used in a conventional still camera or the like.

Next, a sixth embodiment shown in FIG. 44 will be described. The entire configuration of the still video camera is shown in FIG.
Is the same as that shown in FIG. System control circuit 2
A xenon tube 45 provided with a color temperature conversion filter 44 for changing the color temperature of the strobe light, a xenon tube 41 also provided with a color temperature conversion filter 40, and light emission of each xenon tube 45, 41 A charging circuit 50 for storing charge in the main capacitor C3; a trigger circuit 54 for generating a flash signal for each of the xenon tubes 45 and 41; IGBTs 53 and 52, which are switch means for starting and stopping light emission of the light sources 45 and 41, respectively. Note that the color temperature conversion capability Ta of the filter 44 is determined by using a filter and a plurality of xenon tubes in order to control the combined emission color temperature of the strobe device 25 if the entire strobe device 25 is used. Is controlled by the IGBT 52 and the connection between the trigger electrodes of the xenon tubes 41 and 45 and the trigger circuit 54 is controlled.
The cutoff is performed by the photo MOS relays 72 and 75. As a result, despite increasing the number of xenon tubes,
The number of accessory parts can be minimized, and the size of the strobe device can be prevented from increasing.

FIG. 43 shows a fifth embodiment of the present invention. In this figure, the same reference numerals are given to the same circuits as in the fourth embodiment. In the fifth embodiment, the trigger circuit 54 is connected to the common ground signal line S10. The low voltage side coil of the trigger transformer T1 is connected to the other end of the resistor R5 via the trigger capacitor C1 and to the anode terminals of the diodes D5 and D4.

The cathode terminal of the diode D5 is connected to the cathode terminal of the xenon tube 45 and the collector terminal of the IGBT 53, and the cathode terminal of the diode D4 is connected to the cathode terminal of the xenon tube 41 and the collector terminal of the IGBT 52. The base terminals of the IGBTs 52 and 53 are connected to the system control circuit 22, and the light emission trigger signals S3 and S4 output from the system control circuit 22 turn on the IGBTs 53 and 52, respectively, so that operating current flows through the IGBTs 53 and 52.

When IGBT 52 is turned on, diode D
4 and when the IGBT 53 is turned on, the charge of the trigger capacitor C1 is discharged via the diode D5, so that a current flows through the low voltage side coil of the trigger transformer T1 and a trigger signal is induced in the high voltage side coil. Is done. This trigger signal is applied to the trigger electrodes of the xenon tubes 41 and 45, and is used to generate a flash in each xenon tube. However, if the IGBTs 52 and 53 are not turned on, no current flows through each xenon tube.
By selecting ON / OFF of 2, 53, it is possible to select in which xenon tube the flash is generated.

The system control circuit 22 includes a release switch 33 provided on the still video camera body.
And a timer circuit 34, and various controls necessary for photographing are performed by the system control circuit 22 in accordance with the operation of the release switch 33. Also,
Between the system control circuit 22 and the charging circuit 50, a charge start signal S2 for instructing charge accumulation in the main capacitor C3, that is, a charge start, and a main capacitor C3
And a charge completion signal S1 notifying that charging of the battery has been completed. Light control is performed using a photometric sensor 28 composed of a photodiode or the like shown in FIG. 3, an operational amplifier 60, a comparator 61, and a strobe dimming circuit 29 composed of a D / A converter 62. Will be

The operation of the present embodiment will be described. The outline of the photographing process in the sixth embodiment is shown in FIG.
The description is omitted because it is the same as that of the fifth embodiment.

The light emission control of the strobe device 25 using the color temperature conversion filters 44 and 40 having the color temperature conversion capabilities Ta and Tb will be described. FIGS. 45 and 46 show flowcharts of strobe emission control according to the present embodiment. In this figure, the ratio A: B of the light emission amount of the xenon tubes 45 and 41 is determined by the system control circuit 22 so as to match the measured value of the color temperature of the light F4.

The emission ratio A: B is determined according to the control target value of the combined emission color temperature of the strobe device 25, as in the above-described embodiment.
When controlling the overall emission color temperature to a higher color temperature, the emission amount of the xenon tube 41 is increased and the emission amount of the xenon tube 45 is decreased. Determined ratio A:
By B, control is performed such that the xenon tube having a small light emission amount emits light first. For example, when the ratio A <the ratio B, the xenon tube 45 emits light first. in this way,
The xenon tube to be illuminated first is determined, and the maximum emission time La of the xenon tube to be illuminated (hereinafter, the case where the xenon tube 45 is illuminated first) is determined from the data table stored in the memory of the system control circuit 22. , Based on the measured color temperature.

The data of the maximum light emission time La is set in the timer circuit 34 via the signal S15.
Is started (step 263). When the measurement time exceeds the maximum light emission time La, the time-over signal S1
4 from the timer circuit 34 to the system control circuit 2
2 is input.

In order to perform dimming control, an appropriate integral value Ma (digital data) corresponding to the xenon tube 45 is output from the system control circuit 22 to the D / A converter 62 (step 264, see FIG. 3). This proper integration value Ma is a value corresponding to the ratio A of the xenon tube 45, and is obtained from the measured color temperature of the light F4 using the data table stored in the memory of the system control circuit 22. The proper integration value Ma input to the D / A converter 62 is
The signal is converted into an analog voltage signal S8,
1 is output.

Further, the integration start signal S5 is input from the system control circuit 22 to the reset switch 66,
The integration circuit composed of the operational amplifier 60 and the like is reset (step 265). Thereafter, integration is started (step 266). As a result, the light current of the photometric sensor 28 is integrated over time.

At the start of integration in step 266, IGB
At T53, the light emission trigger signal S3 is output from the system control circuit 22 (step 267). The output of the light emission trigger signal S3 turns on the IGBT 53, and the electric charge stored in the trigger capacitor C1 flows toward the common ground signal line S10 via the diode D5 and the IGBT 53.

A current flows through the low-voltage side coil of the trigger transformer T1 due to the discharge of the trigger capacitor C1, and a high-voltage trigger signal is induced in the high-voltage side coil of the trigger transformer T1. The trigger signal guided to the high voltage side coil is applied to the trigger electrode of the xenon tube 45,
Xenon gas inside is ionized. Due to the ionization of the xenon gas, the resistance between the anode and cathode terminals sharply decreases, a spark current flows from the anode terminal to the cathode terminal, a flash is generated, and the strobe light F3 is emitted toward the subject 35.

The reflected light F4 arriving from the subject 35 increases due to the strobe light F3, and when the integrated value output from the integrating circuit including the operational amplifier 60 and the like reaches the appropriate integrated value Ma, the quench signal S6 is changed to the comparator. 61
Is input to the system control circuit 22. The presence or absence of the input of the quench signal S6 is determined in the system control circuit 22 (step 268). If the quench signal S6 is input, the light emission trigger signal S3
Is stopped (step 270).

When the light emission trigger signal S3 stops, the IGBT 53
Is turned off, the current flowing through the xenon tube 45 is cut off, and the flash emission of the xenon tube 45 is stopped. If the quench signal S6 is not input, the timer circuit 34
The system control circuit 22 determines whether or not a time-over signal S14 has been input from the controller (step 26).
9). If the time-over signal S14 has not been input, the process returns to step 268, and it is determined again whether or not the quench signal S6 has been input. Conversely, when the time-over signal S14 is input, the output of the light emission trigger signal S3 is stopped, and the activation of the xenon tube 45 is stopped (step 270). After the output of the light emission trigger signal S3 is stopped, the timer circuit 3
4 is stopped (step 271), and thereafter, light emission of the xenon tube 41 is started.

In FIG. 46, first, the maximum light emission time Lb of the xenon tube 41 is obtained in the system control circuit 22 from the data table based on the measured color temperature of the light F4. This maximum light emission time Lb corresponds to the signal line S15.
Is set in the timer circuit 34 through the timer circuit 3
4 is started (step 272). Next, in order to perform dimming control of the xenon tube 41, the xenon tube 41 is used based on the measured color temperature of the light F4 using the data table stored in the memory of the system control circuit 22.
The appropriate integral value Mb (digital data) corresponding to the light emission ratio B is output to the D / A converter 62 (step 27).
3). Appropriate integral value Mb input to D / A converter 62
Is converted into an analog voltage signal S8 and output to the comparator 61. The proper integration value Mb is a threshold value for maintaining the ratio A: B and determining that the amount of reflected light from the subject 35 has reached an amount at which an optimum image can be obtained, as in the case of the proper integration value Ma. is there.

The reset switch 66 is turned on by the integration start signal S5, and the integration circuit is reset (step 274). Then, integration in the integration circuit is started (step 275). Thereafter, the light emission trigger signal S4 is output to the IGBT 52, and light emission of the xenon tube 41 is started (step 276). Then, the comparator 61
When the quenching signal S6 is input from the controller or the time-over signal S14 is input from the timer circuit 34, the output of the light emission trigger signal S4 is stopped and the xenon tube 41 is stopped.
Is stopped (step 279). Thereafter, the time counting operation of the timer circuit 34 is stopped (step 28).
0). After the light emission control of the xenon tubes 45 and 41 is completed in this way, depending on conditions, the charge start signal S2 is output again from the system control circuit 22 to the charging circuit 50, and the next flash light emission control is performed. The charging of the main capacitor C3 is started.

In the present embodiment, the trigger circuit 54 is shared by the xenon tubes 45 and 41, and the IGBT which is a switch for switching off and on the xenon tubes 45 and 41 is provided independently for each xenon tube. The switch means may be shared by the xenon tubes, the trigger circuit may be provided independently for each xenon tube, and the trigger circuit may be turned on and off independently by the system control circuit 22. Thus, the light emission of a plurality of xenon tubes can be independently controlled by a plurality of trigger circuits, and the emission and stop of each xenon tube can be alternately repeated. As a further application, the switch means and the trigger circuit may be provided independently for each xenon tube.

FIG. 47 shows a seventh embodiment of the present invention. In this figure, the same circuits as those in the sixth embodiment are denoted by the same reference numerals. In the seventh embodiment, a color temperature conversion filter 44 having a color temperature conversion capability Ta that satisfies the above equation (4) and a color temperature conversion filter 44 that satisfies the above equation (5) are provided in front of the projection surface of one xenon tube 45. And a color temperature conversion filter 40 having a color temperature conversion capability Tb.
The emission color temperature is changed by switching the filter located in front of the light emitting surface, and the combined emission color temperature of the entire flash device 25 is controlled. 48 to 50 show detailed views of a strobe light projecting portion used in the present embodiment.

FIG. 48 shows a strobe device 2 according to the seventh embodiment.
49 and 50 are horizontal cross-sectional views of the strobe device 25 taken along the line XX in FIG. 48. As shown in these figures, a xenon tube 45 is mounted in an opening 285 located at the center of the strobe device 25, and a reflector 286 for reflecting strobe light forward is provided behind the xenon tube 45. I have. The strobe device 25 sandwiched between the reflector 286 and the opening 285
Are provided with color temperature conversion filters 44 and 40 suspended from the slider 283.

Gear teeth are provided on one surface of the slider 283. The gear teeth mesh with a gear 284 rotated by a motor 282, and the color temperature conversion filters 44 and 40 are rotated by forward and reverse rotation of the motor 282. The light is moved in front of the light emitting surface of the xenon tube 45. The motor 282 is connected to a motor drive circuit 281, and the motor drive circuit 281 is connected to the system control circuit 22. Based on a command from the system control circuit 22, the motor drive circuit 281 rotates the motor 282 forward and reverse, thereby replacing the color temperature conversion filters 44 and 40 located in front of the xenon tube 45. Other configurations are substantially the same as in the sixth embodiment. However, because of the single xenon tube, there are no diodes D4 and D5 and the IGBT 53
The light emission and stop of the xenon tube 45 are controlled by ON and OFF.

The operation of the seventh embodiment will be described. FIG.
1 and 52 show flowcharts of strobe light emission control in this embodiment. Note that the entire shooting processing of the still video camera to which this embodiment is applied is the same as the processing (shown in FIG. 32) in the second embodiment, and a description thereof will be omitted. In the color measurement process before the strobe light emission control, the ratio A: B of the light emission amount of the xenon tube 45 performed using the color temperature conversion filter 44 or the color temperature conversion filter 40 is determined according to the measured color temperature of the light F4.

That is, the amount of light emitted from the xenon tube 45 emitted when the color temperature conversion filter 44 is moved to the front of the light projecting surface, and
The color temperature conversion filter 40 is moved in front of the light projecting surface, and the ratio A: B to the amount of light emitted from the xenon tube 45 emits light F.
4 is determined according to the color temperature.

When a filter corresponding to a small ratio is used according to the obtained ratio A: B (hereinafter, A <B,
A description will be given of a case where light emission is first performed using the color temperature conversion filter 44). The maximum light emission time La is obtained from a data table stored in the memory of the system control circuit 22. The data of the obtained maximum light emission time La is set in the timer circuit 34, and the timer circuit 34 starts the time counting operation (step 287).

The motor 282 is driven so that the filter having a small emission ratio, here the color temperature conversion filter 44, is located in front of the light projecting surface of the xenon tube 45 (step 28).
8). The ratio A determined from the color temperature value of the light F4:
If B>A> B, the color temperature conversion filter 40 is moved before the xenon tube 45, and the following processing is performed.

Next, in order to perform the dimming control, the proper integration value Ma (digital data) when the color temperature conversion filter 44 is used is converted into the light F4 using the data table stored in the memory of the system control circuit 22. , And is output to the D / A converter 62 (step 289). The proper integration value Ma is a value corresponding to the ratio A, and is converted into an analog voltage signal S8 by the D / A converter 62 and output to the comparator 61. After the integration circuit including the operational amplifier 60 is reset by the integration start signal S5 (step 29)
0), integration is started (step 291). Thus, the dimming control based on the accumulated light amount of the reflected light F4 is started.

At the start of the integration of the amount of light received by the photometric sensor 28, a light emission trigger signal S3 is output, and the xenon tube 45
Is started (step 292). The dimming control determines whether the quench signal S6 has been input in the system control circuit 22 (step 2).
93). When the quench signal S6 is input, the output of the light emission trigger signal S3 is stopped, and the light emission of the xenon tube 45 is stopped (step 295).

However, when the quench signal S6 is not input, the system control circuit 22 determines whether a time-over signal has been input from the timer circuit 34 (step 294). If the time-over signal has not been input, the flow returns to the determination at step 293. Conversely, if there has been input, the output of the light emission trigger signal S3 is stopped and the light emission of the xenon tube 45 is stopped (step 295). Then, the timing operation of the timer circuit 34 is stopped (step 296). Next, a filter having a large light emission ratio determined by the measured color temperature, here the maximum light emission time Lb corresponding to the color temperature conversion filter 40, is read from the data table and set in the timer circuit 34. Is started (step 33 in FIG. 52).
0).

The color temperature conversion filter 40 is replaced with the color temperature conversion filter 44 by driving the motor 282.
5 is moved before (step 331). In order to perform dimming control of the xenon tube 45 with the color temperature conversion filter 40, an appropriate integral value Mb obtained from the measured color temperature of the light F4
Is set in the D / A converter 62 (step 332).
Then, after resetting the integration circuit (step 333), integration is started (step 334), and thereafter, a light emission trigger signal S3 is output and light emission of the xenon tube 45 is started again (step 335).

It is determined whether the quench signal S6 from the comparator 61 is input by the dimming control and whether the time-over signal S14 is input from the timer circuit 34 (steps 336 and 337). When the quench signal S6 or the time-over signal S14 is input, the output of the light emission trigger signal S3 is stopped (step 33).
8), the light emission of the xenon tube 45 is stopped. Then, the timing operation of the timer circuit 34 is stopped (step 33).
9).

When the strobe light emission control is completed as described above, the signal charges stored in the CCD 11 are read out as image signals, converted into image signals of a predetermined format by the signal processing circuit 15, and then stored in the recording circuit 19. Is recorded on the recording medium M. Then, depending on the conditions,
The charge start signal S2 is again output to the system control circuit 22.
Is output to the charging circuit 50 to prepare for the next new strobe light emission control.

As described above, in the seventh embodiment, the color temperature conversion filter 44 determined by the equation (4) and the color temperature conversion filter 40 determined by the equation (5) are selected according to the color temperature range to be controlled. Is provided in front of the xenon tube 45 so as to be exchangeable. In addition, the ratio of the light emission amount of the xenon tube 45 when the color temperature conversion filter 44 is in front of the light emitting surface to the light emission amount of the xenon tube 45 when the color temperature conversion filter 40 is in front of the light emitting surface is determined by the light F4. The color temperature is determined based on the color temperature, and the combined emission color temperature of the entire flash device 25 is adjusted. Further, in order to prevent the light emission amount of the xenon tube 45 using one of the color temperature conversion filters from being excessively increased by the dimming control, the light F4 is set to the light emission time of the xenon tube 45 in each color temperature conversion filter. A restriction was made based on the color temperature.

As a result, it is possible to accurately adjust the combined emission color temperature of the strobe device in accordance with the color temperature of light, and more natural still video shooting becomes possible. In addition, it is possible to prevent the amount of light emitted from the xenon tube from increasing when one of the color temperature conversion filters is used by dimming control, and to prevent the combined emission color temperature of the strobe device from deviating from the target value.

According to the sixth and seventh embodiments, it is possible to easily specify which color temperature conversion capability should be used for the primary color temperature of the xenon tube and the control target color temperature range, and The combined emission color temperature of the strobe device can be controlled more accurately. In addition, since an accurate filter can be used for the control target color temperature range, even if the amount of light emitted from the xenon tube fluctuates slightly due to the amount of charge stored in the main capacitor at the time of light emission, the strobe due to the change in the amount of light emitted The deviation of the combined emission color temperature of the device from the target value can be minimized.

Further, since the color temperature conversion filter can be specified, light of various color temperatures can be generated regardless of the color temperature of the light emitting means. For example, when a xenon tube is used as the light emitting means as in each of the above-described embodiments, light having a color temperature corresponding to general natural light or artificial light such as a fluorescent light can be generated. This makes it possible to obtain an excellent photographed image.

Next, as an eighth embodiment, an example in which a plurality of xenon tubes emit light simultaneously will be described. FIG. 53 is a timing chart showing the shooting operation in this embodiment. The circuit configuration is the same as that shown in FIGS.

When the shutter release switch is fully pressed (reference W1), the colorimetric sensor 23 and the colorimetric control circuit 24
Operates (symbol W2), and the R / G signal and B / G
The signal is input to the system control circuit 22. In the system control circuit 22, a strobe control signal is calculated based on these signals (reference W3). This strobe control signal is transmitted to the first and second xenon tubes 4.
This corresponds to the light emission time of 5, 41.

When the operation of the strobe control signal is completed, the first and second light emission start signals W are output from the strobe device 25.
4, W5 are output simultaneously, whereby the first and second
Xenon tubes 45 and 41 start emitting light. Then, at the timing based on the strobe control signal, the first and second light emission stop signals W6 and W7 are output, whereby the light emission of the first and second xenon tubes 45 and 41 is stopped respectively. That is, the first xenon tube 45 starts light emission at the rise of the light emission start signal W4, and stops light emission at the rise of the light emission stop signal W6.
Further, the second xenon tube 41 starts emitting light when the emission start signal W5 rises, and stops emitting light when the emission stop signal W7 rises.

First and second xenon tubes 45 and 41
Have basically the same performance, and the light intensity W after the start of light emission
8 and W9 have the same temporal change, and a predetermined light amount can be obtained by controlling the light emission time. This light amount corresponds to the area of the hatched portion in FIG.
That is, in this example, the amount of light obtained through the first xenon tube 45 and the first color filter 44 is relatively small,
The amount of light obtained via the second xenon tube 41 and the second color filter 40 is relatively large. Therefore, the spectral distribution of the strobe light detected by the CCD 11 is consequently
The result is as shown in FIG. In other words, the same effect as when the strobe light emits strobe light having substantially the same color temperature as the external light can be obtained.

The charge accumulation in the CCD 11 is started immediately before the rising of the first and second light emission start signals W4 and W5, and the charge accumulation time W10 is determined by the xenon tubes 45 and 41. It is much longer than the light emission time. In the eighth embodiment, the light emission start timings of the first and second xenon tubes 45 and 41 are the same. However, the light emission start and light emission stop of these xenon tubes 45 and 41 may be performed completely separately. It may be performed at least during the charge accumulation time W10.

FIG. 54 is a block diagram showing a still video camera according to the ninth embodiment. In this embodiment, between the first xenon tube 45 and the first color filter 44, and between the second xenon tube 41 and the second color filter 40
Between the first and second liquid crystal filters 43, respectively.
3, 434 are provided. These liquid crystal filters 4
33 and 434 are controlled by the system control circuit 22, whereby the light transmittance changes. In this embodiment, the light emission times of the first and second xenon tubes 45 and 41 are the same, and by controlling the respective transmittances of the liquid crystal filters 433 and 434, the color filters 4
The intensity of light passing through 4, 40 changes, thereby controlling the spectral distribution of strobe light.

FIG. 55 shows a timing chart in this embodiment. In this figure, reference numerals W11 and W12 are control signals for the first and second liquid crystal filters 433 and 434, respectively, and the control is performed such that the transmittance of the liquid crystal filter increases as the amplitude of the signal increases. In this embodiment, the first and second
The xenon tubes 45 and 41 start emitting light at the same time and stop emitting light at the same time. However, the xenon tubes 45 and 41 only need to have the same emission time.
The light emitting operations of 5 and 41 may be performed independently.

As described above, according to the eighth and ninth embodiments, control can be performed such that the color temperature of the strobe light is close to the color temperature of the object. Accordingly, appropriate white balance adjustment is performed over the entire image, and the appearance of a color that is deviated toward the red side or the blue side over the entire screen is prevented. Also, usually strobe light is close to daylight color,
Conventionally, the daylight illumination is forcibly performed by the strobe light even when the daylight illumination is not desired. However, according to the eighth and ninth embodiments, the strobe light has the same color temperature as the external light. Since the same effect can be obtained, the strobe device plays the role of the original auxiliary light, and can obtain natural color reproduction.

In the eighth and ninth embodiments, the light emission time of the xenon tubes 45 and 41 or the liquid crystal filter 43
Although the color temperature of the strobe light is changed by controlling the light amount of the strobe device by controlling the transmittances of the light sources 3 and 434, it is also possible to change the properties of the gas in the xenon tubes 45 and 41. Also, the color temperature of the strobe light can be controlled by changing the voltage applied to the xenon tubes 45 and 41.

The color temperature conversion filters used in the above embodiments are not limited to two types, and three or more types of color temperature conversion filters may be used. For example, when three or more types of color temperature conversion filters are used in the sixth embodiment, a xenon tube dedicated to each filter is provided,
The amount of light emitted from each xenon tube is controlled based on the color temperature of the light F4. In the seventh embodiment, the respective color temperature conversion filters are provided so as to be movable in front of the light projecting surface of the xenon tube 45 by the motor 282, and the light emission amount of the xenon tube when each filter is used is set to the color temperature of the light F4. Control according to.
Thus, the combined emission color temperature of the strobe device 25 can be freely controlled.

In each of the above embodiments, the switch means for controlling light emission / stop of each xenon tube is also IG.
Although the BTs 52 and 53 are used, this may be performed using a plurality of thyristors, and the present invention is not particularly limited to IGBTs. The means for measuring the strobe reflected light from the subject 35 and the means for generating a quench signal are not limited to the operational amplifier and the analog comparator as shown in FIG. 3, and the digital circuit may constitute an integrating circuit and a comparing circuit. Good. Although a xenon tube is used as a light source as a light source in each of the embodiments, the light source is not limited to this, and any device may be used as long as it can repeatedly generate and stop a flash by turning on and off a current.

In each embodiment, the photometric sensor 2
8. The light from the subject incident on the colorimetric sensor 23 is C
Light incident through a photographic lens system provided in the CD 11 may be used. By doing so, CC
The amount of light incident on D11 can be measured more accurately, and more accurate dimming control and color temperature control can be performed.

Further, in each of the above embodiments, a still video camera has been described. However, the present invention can be applied to a strobe device including a strobe device 25, a colorimetric sensor 23, a photometric sensor 28, and the like. That is, if the present invention is applied to a strobe device without a still video photographing circuit such as the CCD 11, the signal processing circuit 15, and the recording circuit 19, it can be used for a conventional still camera without a strobe device.

[0231]

As described above, according to the present invention, it is possible to obtain an effect that a good color reproduction can always be realized on a photographing screen using strobe light emission.

[Brief description of the drawings]

FIG. 1 is a configuration circuit diagram of an entire still video camera according to a first embodiment of the present invention.

FIG. 2 is a diagram showing the ratios of R / G and B / G components in white.

FIG. 3 is a detailed diagram of a photometric sensor, an integration circuit, and a comparison circuit.

FIG. 4 is a circuit diagram of a flash device according to the first embodiment of the present invention.

FIG. 5 is a circuit diagram of a filter control circuit according to the first embodiment.

FIG. 6 is an explanatory diagram of a GH liquid crystal cell used in the strobe device of the first embodiment.

FIG. 7 is a timing chart of a shooting process of the still video camera in the first embodiment.

FIG. 8 illustrates a second example of the strobe light emitting unit according to the first embodiment.
It is a cross-sectional view of three examples.

9 is a diagram showing a front view of the strobe light projecting unit shown in FIG.

FIG. 10 is a diagram showing fourth and fifth examples of a strobe light projecting unit in the first embodiment.

FIG. 11 is a diagram showing sixth and seventh examples of a strobe light projecting unit according to the first embodiment.

FIG. 12 is a diagram illustrating an eighth example of a strobe light projecting unit in the first embodiment.

FIG. 13 is a diagram illustrating an application example of the liquid crystal cell according to the first embodiment.

FIG. 14 is a block circuit diagram of a still video camera according to a second embodiment of the present invention.

FIG. 15 is a circuit diagram of a second embodiment of a strobe device according to the present invention.

FIG. 16 is a diagram illustrating a first configuration example of a strobe device according to a second embodiment.

FIG. 17 is a diagram illustrating a second configuration example of the strobe device according to the second embodiment.

FIG. 18 is a diagram illustrating a third configuration example of the strobe device according to the second embodiment.

FIG. 19 is a diagram illustrating a fourth configuration example of the strobe device according to the second embodiment.

FIG. 20 is a diagram illustrating a fifth configuration example of the strobe device according to the second embodiment.

FIG. 21 is a diagram illustrating a sixth configuration example of the strobe device according to the second embodiment.

FIG. 22 is a diagram illustrating a seventh configuration example of the strobe device according to the second embodiment.

FIG. 23 is a diagram illustrating white balance characteristics under a plurality of different color temperatures.

FIG. 24 is a diagram showing a color temperature of a light source.

FIG. 25 is a diagram illustrating an example of a spectral distribution of strobe light.

FIG. 26 is a diagram illustrating control of the color temperature of strobe light according to the second embodiment of the present invention.

FIG. 27 is a diagram showing a relationship in which the primary color temperature of the xenon tube is positioned at the upper part of the color temperature range converted by each color temperature conversion filter.

FIG. 28 is a diagram showing a relationship in which the primary color temperature of the xenon tube is located in the middle of the color temperature range converted by each color temperature conversion filter.

FIG. 29 is a diagram showing a relationship in which the primary color temperature of the xenon tube is located at the lower part of the color temperature range converted by each color temperature conversion filter.

FIG. 30 is a diagram showing a displacement amount from a target color temperature when a light emission amount of a xenon tube slightly changes in a color temperature range which can be controlled by each color temperature conversion filter.

FIG. 31 is a diagram illustrating a displacement amount from a target color temperature when a light emission amount of a xenon tube slightly changes in a range controlled by each color temperature conversion filter having a higher color temperature conversion ability than FIG. 30;

FIG. 32 is a sequence diagram of the entire photographing process according to the second embodiment.

FIG. 33 is a view illustrating a flowchart of a process of simultaneously charging a plurality of main capacitors in the second embodiment.

FIG. 34 is a diagram showing a flowchart for separately performing a process of charging a plurality of main capacitors in the second embodiment.

FIG. 35 is a view showing a flowchart for separately performing charging processing for a plurality of main capacitors in the second embodiment.

FIG. 36 is a flowchart of flash emission control according to the second embodiment.

FIG. 37 is a flowchart of strobe light emission control according to the second embodiment.

FIG. 38 is a circuit diagram of a third embodiment of the strobe device according to the present invention.

FIG. 39 is a view showing a flowchart of a process of charging a plurality of main capacitors in the third embodiment.

FIG. 40 is a circuit diagram of a flash device according to a fourth embodiment of the present invention.

FIG. 41 is a flowchart of strobe light emission control according to a fourth embodiment.

FIG. 42 is a flowchart of strobe light emission control according to a fourth embodiment.

FIG. 43 is a circuit diagram of a flash device according to a fifth embodiment of the present invention.

FIG. 44 is a circuit diagram of a flash device according to a sixth embodiment of the present invention.

FIG. 45 is a flowchart of strobe light emission control according to the sixth embodiment.

FIG. 46 is a flowchart of strobe light emission control according to the sixth embodiment.

FIG. 47 is a circuit diagram of a strobe device according to a seventh embodiment of the present invention.

FIG. 48 is a front view of a strobe device according to a seventh embodiment.

FIG. 49 is a sectional view of a strobe device according to a seventh embodiment.

FIG. 50 is a sectional view of a strobe device according to a seventh embodiment.

FIG. 51 is a flowchart of strobe light emission control according to a seventh embodiment.

FIG. 52 is a flowchart of strobe light emission control according to the seventh embodiment.

FIG. 53 is a timing chart of an imaging process according to the eighth embodiment.

FIG. 54 is a block circuit diagram of a still video camera according to a ninth embodiment.

FIG. 55 is a timing chart of the photographing process of the ninth embodiment.

FIG. 56 is an explanatory diagram of a conventional example.

[Explanation of symbols]

 Reference Signs List 11 CCD 12 CDS circuit 13 Color separation circuit 14 White balance adjustment circuit 15 Signal processing circuit 16 Interface circuit 17 Display 18 FM modulation circuit 19 Recording circuit 20 Aperture 22 System control circuit 23 Colorimetric sensor 24 Colorimetric control circuit 25 Strobe device 26 Imaging Element drive circuit 27 Aperture drive circuit 28 Photometric sensor 29 Strobe light control circuit 30 Photometric sensor 31 Photometric circuit 32 Exposure calculation circuit 33 Release switch 34 Timer circuit 35 Subject 36 Imaging optical system lens 40, 44 Color temperature conversion filter 41, 45 Xenon tube

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) H04N 9/73 H04N 9/73 A H05B 41/32 H05B 41/32 D // H04N 101: 00 (31) Priority claim number Japanese Patent Application No. 5-56505 (32) Priority date February 22, 1993 (1993.2.22) (33) Priority claim country Japan (JP) (31) Priority claim number 5-59556 (32) Priority date February 24, 1993 (Feb. 24, 1993) (33) Priority country Japan (JP) (72) Inventor Taihei Morisawa 2-36 Maenocho, Itabashi-ku, Tokyo 9 Asahiko Gaku Kogyo Co., Ltd.

Claims (18)

[Claims] 1. A single flash light emitting means, a color measuring means for measuring a color temperature of a subject, and a color temperature conversion filter provided on the light emitting surface side of the flash light emitting means and having a predetermined spectral transmittance. The flash light emitting means and the color temperature conversion filter so that the color temperature of the light applied to the subject is substantially the same as the measured color temperature based on the color temperature information measured by the color measurement means. Control means for controlling at least one of the following. 2. The flash device according to claim 1, wherein the color temperature conversion filter has a function of lowering a color temperature. 3. The flash device according to claim 1, wherein the color temperature conversion filter has a function of increasing a color temperature. 4. The color temperature conversion filter includes a single filter film composed of a plurality of filter portions having different densities, and the control unit determines that any one of the plurality of filter portions is the same as the flash light emitting unit. The strobe device according to claim 1, further comprising a filter film moving unit that moves the filter film so as to cover the front surface. 5. A guest-host type liquid crystal cell in which the color temperature conversion filter has a liquid crystal substance sandwiched between a pair of transparent substrates, a transparent electrode provided on each of the pair of transparent substrates, and the pair of transparent substrates. The strobe device according to claim 1, further comprising: a polarizing plate provided on a surface of the transparent substrate facing the flash light emitting unit. 6. The flash device according to claim 5, wherein a plurality of the guest-host type liquid crystal cells are provided so as to be stacked. 7. A liquid crystal cell, wherein the color temperature conversion filter has a liquid crystal substance sandwiched between a pair of transparent substrates;
A transparent electrode provided on each of the pair of transparent substrates,
A filter core provided corresponding to a part of the liquid crystal cell;
The flash device according to claim 5, further comprising: 8. The flash device according to claim 7, wherein the liquid crystal cell is a twisted nematic liquid crystal cell. 9. The device according to claim 7, wherein a diffusion plate is provided to face one surface of the pair of transparent substrates, and the filter coat is provided on a part of the surface of the diffusion plate. Strobe device. 10. The flash device according to claim 9, wherein the filter coat is provided at the center of the diffusion plate. 11. The flash device according to claim 9, wherein the filter coat is provided on a surface of the diffusion plate by vapor deposition. 12. The flash device according to claim 7, wherein the transparent electrode is provided only in a portion corresponding to the filter coat. 13. The flash device according to claim 7, wherein the transparent electrode is provided only in a portion not corresponding to the filter coat. 14. A flash light emitting device comprising: a slider provided movably with respect to said flash light emitting means; and a drive mechanism for moving said slider, wherein said color temperature conversion filter is provided on said slider, and said flash light emission is provided. 2. A strobe device according to claim 1, wherein the strobe device is selectively arranged before the means. 15. The color temperature conversion filter includes first and second color temperature conversion filter elements, and the control means controls the first color temperature conversion filter when the first color temperature conversion filter is disposed before the flash light emitting means. 15. The control unit according to claim 14, wherein a ratio of a light emission amount of the flash light emitting unit to a light emission amount of the flash light emitting unit when the second color temperature conversion filter is disposed before the flash light emitting unit is controlled. The strobe device according to item 1. 16. The flash color temperature of the flash light emitting means is Kc.
[K], and when the color temperature of light obtained through the color temperature conversion filter is Ka [K], the color temperature conversion filter has a color temperature conversion capability Ta represented by the following equation (1). The strobe device according to claim 1, further comprising: Ta = (10 ⁶ / Ka) − (10 ⁶ / Kc) [Mired] (1) 17. A single flash light emitting means having an emission color temperature of Kc [K], a first color temperature conversion filter having a color temperature conversion ability Ta represented by the following equation (2), and ), A second color temperature conversion filter having a color temperature conversion capability Tb, and the first and second color temperature conversion filters are selectively moved before the light emitting surface of the flash light emitting means. Moving means, the first and second
From the color temperature Ka [K] to the color temperature Kb [K] (K
A strobe device characterized in that control is possible during a <Kb). Ta ≧ (10 ⁶ / Ka) − (10 ⁶ / Kc) [Mired] (2) Tb ≦ (10 ⁶ / Kb) − (10 ⁶ / Kc) [Mired] (3) 18. A flash device according to claim 1 or 17, and a photometric unit for measuring an amount of light coming from a subject.
Light emission stopping means for stopping light emission of the flash light emitting means when the amount of light measured by the light measuring means reaches a predetermined amount; an image sensor for converting a subject image into an image signal; and a color temperature measured by the color measuring means. A still video camera comprising: a white balance adjusting unit that adjusts a white balance of an image signal output from an image sensor in response to the white balance.