JPS6136986Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to an electronic flash device for multiple flashes that is installed on the camera side to prevent insufficient light intensity of the electronic flash device and shadows on the subject that occur when using the electronic flash device. The present invention relates to an electronic flash device for multiple flashes that is equipped with a light receiving circuit that can optically detect the start and stop of light emission of a main electronic flash device (hereinafter referred to as the main flash device), and controls the start and stop of light emission by itself.

There is a conventional device of this kind as seen in Japanese Patent Application Laid-Open No. 139731/1983, but in this device, the amount of light emitted by the auxiliary electronic flash device for multiple flashes is higher than that of the electronic flash device for main flash. If they are larger or the same, when the electronic flash device for main flash stops firing, the light receiving part of the electronic flash device for auxiliary flash is in the state of receiving the auxiliary light, so stop the main flash. This may result in overexposure that cannot be detected and the electronic flash device for multiple flashes may stop emitting light.

The present invention solves this problem, and when using a sub-flash device, the main flash device and the sub-flash device are optically coupled, and the sub-flash device is synchronized with the light emission of the main flash device installed on the camera side. Activate the flash device to cause the sub-flash device to emit light, illuminate the subject with the light emitted from both the main flash device and the sub-flash device, and then distribute the reflected light from the subject due to the light irradiation to the main flash device. The installed light receiving circuit performs light receiving and integrating operations, and when its output reaches a predetermined value, the trigger circuit of the received light amount control circuit is activated, and the main discharge capacitor is activated by the light amount control bypass tube. The remaining energy is bypassed to stop the main flash, and at the same time it is placed on the side of the sub-flash device and does not respond to the light emitted by the sub-flash device, but is sensitive to light at a wavelength to which the film of the main flash device is not sensitive. A photoresponse circuit consisting of a light receiving sensor, a differential capacitor, etc. optically detects the light emission operation of the main flash device mentioned above and generates a light emission signal and a light emission stop signal, thereby automatically causing the sub flash device to emit light and stop light emission. The purpose of this method is to irradiate the subject with appropriate exposure, and will be explained below with reference to the drawings.

FIG. 1 is an electric circuit diagram showing an electronic flash device according to an embodiment of the present invention, and FIG. 2 is a characteristic diagram of an optical filter used in the embodiment shown in FIG.

1 is a main flash device, 2 is a sub-flash device, and an optical filter 30 having light characteristics as shown in FIG. The light output distribution is changed by blocking wavelengths in the infrared and ultraviolet regions, which the film is not sensitive to, without affecting the photographic effect, and changing the light output distribution to the wavelengths in the sensitive region of the photographic film, in other words, in the generally called light region. The light receiving sensor 20 of the sub-flash device 2 is designed to transmit wavelengths.
An optical filter 22 having characteristics as shown in FIG. The sensor 20 is configured to be sensitive only to light emitted from the main flash device 1 that includes wavelengths in the infrared region. Further, in front of the light receiving sensor 19 of the main flash device 1, an optical filter 3 disposed in front of the flash discharge tube of the sub-flash device described above is installed.
An optical filter 21 having the same characteristics as 0 is provided. This is because the light receiving circuit of the main flash device receives the light reflected from the subject by both the main flash device and the sub flash device, and determines the appropriate amount of light at a certain level determined by the integrating capacitor that integrates the light. This is because it is designed to be detected.

Therefore, by arranging the optical filter 21 that transmits only light in the wavelength range to which the film is sensitive in front of the light-receiving element 19, the light-receiving element 19 can protect the film from changing even when the wavelength distribution of reflected light changes. Since only changes within the sensitive wavelength region are received, there is almost no effect on the integral value of the integrating condenser 31, and an appropriate amount of light can be obtained.

Next, its operation will be explained.

Now, when the photographer turns on the power switches 3 and 4 of the main flash device 1 and the sub flash device 2, the oscillation transistors 5 and 6, the oscillation transformer 7,
8, the well-known DC- consisting of diodes 9, 10, etc.
DC converters 11 and 12 start operating, and main capacitors 15 and 16 are charged to a predetermined voltage value. Therefore, when the photographer releases the shutter of a photographic camera equipped with a main flash device,
The synchro switch 17 is closed and the flash discharge tube 40 of the main flash device 1 emits light, and this light emission and the reflected light from the subject 18 due to this light emission enter the light receiving sensor 20 through the filter 22 of the light response circuit of the sub flash device 2. do. As a result, the optical filter 2
2 allows only light in the infrared wavelength range to pass through, and the light output in the shaded area shown in FIG.
4. A current is supplied to the SCR 29 through the path of the base capacitor 25, the light receiving sensor 20, the capacitor 26, and the resistor 28, the SCR 29 becomes conductive, and the flash discharge tube 41 of the sub-flash device 2 emits light. The output of the light emitted from the sub-flash device 2 is filtered through an optical filter 30 disposed in front of the flash discharge tube 41 of the sub-flash device 2.
However, as mentioned above, the optical filter 30 passes only the light in the wavelength range that the film is sensitive to, that is, the light in the wavelength range of approximately 320 to 750 nm. The light output is irradiated onto the subject 18 as light output only in the wavelength range.

The light output emitted from both the main flash device 1 and the sub flash device 2 is reflected from the subject 18 and reaches the light receiving sensor 19 of the main flash device 1, but the light receiving sensor of the main flash device 1 as described above 19, due to the effect of the optical filter 21 placed in front, the film of the reflected light that reaches it is sensitive only to light in the wavelength range to which it is sensitive, and each optical output is converted into a photocurrent and charges the integrating capacitor 31. will be accomplished. When the voltage charged in the integrating capacitor 31 reaches a predetermined level, the trigger circuit 23 operates, the light amount control bypass tube 24 becomes conductive, and the charging energy of the main discharge capacitor 15 is bypassed to discharge the main flash device 1. Light emission stops.

On the other hand, as described above, even when the main flash device 1 and the sub flash device 2 are emitting light, the light receiving sensor 20 of the sub-flash device 2 operates in the shaded area shown in FIG. 3, that is, the light receiving sensor 20 shown in FIG. The light output in the wavelength range determined by the spectral sensitivity characteristics and the spectral transmission characteristics shown in FIG. It is sensitive to infrared light included only in the light output of the main flash device 1. A photocurrent flows due to the incidence of light from the main flash device, and current is supplied to the differential capacitor 26 from the power source 14 and the base capacitor 25 to charge the differential capacitor 26, and the sub flash device emits light. Thereafter, when light in the infrared region is no longer applied to the light receiving sensor 20 as the main flash device stops emitting light, the photocurrent stops flowing, and the charges stored in the differential capacitor 26 are transferred to the resistor 3.
2. It is discharged through the emitter, base, and resistor 33 of the transistor 34, and is supplied to the transistor 34 as a base current, so that the transistor 34 becomes conductive. Therefore, a current is supplied from the Zener voltage power supply 35 generated by the light emission of the sub-flash device 2 through the loop of the transistor 34, the resistor 36, and the gate of the SCR 37, that is, the SCR 37 is turned on at the same time as the main flash device 1 stops emitting light. The charge stored in the trigger capacitor 38 is discharged via the trigger coil 39, the light quantity control bypass pipe 42 is made conductive, and the sub-flash device 2 stops emitting light. In this way, the flashing and stopping of the sub-flash device is controlled only by the light-emitting operation of the main flash device, and since no light enters the light receiving sensor 20 of the sub-flash device after the main flash device stops emitting light, The light emitting stop operation of the flash device can be performed reliably.

In addition, in the above embodiment, the light receiving sensor 1
9 and 20, the optical filters 21 and 22 having the characteristics shown in FIG. If you use something that is sensitive to the wavelength range,
No optical filter is required. In addition, the circuit that controls the amount of light emitted by the main and sub-flash devices is of the so-called bypass type using a bypass tube that bypasses the charging energy of the main discharge capacitor connected in parallel to the flash discharge tube. It is also possible to implement a so-called series system in which the conduction of switch elements connected in series is controlled.

As described above, in the present invention, the light receiving circuit of the main flash device operates based on the sensitivity to the light wavelength of the film, and the light receiving circuit of the sub flash device is configured so that the light receiving circuit of the main flash device operates based on the sensitivity to the light wavelength of the film. The film is designed to be sensitive only to light in the wavelength range to which it is sensitive, and the sub-flash unit outputs light only in the wavelength range to which the film is sensitive, so that the sub-flash unit emits light only in the wavelength range to which the film is sensitive. And, it is possible to provide an electronic flash device for multiple flashes, which increases the sensitivity to light emission stoppage, can reliably stop the light emission of the sub-flash device, and allows multi-flash photography without causing exposure errors. be.

[Brief explanation of the drawing]

FIG. 1 is an electric circuit diagram of an electronic flash device for multiple flashes according to an embodiment of the present invention, and FIGS. 2a, b, and c are characteristic diagrams of optical filters used in the embodiment shown in FIG. FIG. 3 is a characteristic diagram of the light output characteristic of the light receiving element. 1... Main flash electronic flash device, 2... Electronic flash device for multiple flashes, 15, 16... Main capacitor, 19,
20... Light receiving element, 21, 22, 30... Optical filter, 40, 41... Flash discharge tube, 18...
…subject.

Claims (1)

[Utility Model Claims] (1) A main electronic flash device that detects the emission of light from a main electronic flash device and is optically coupled to the main electronic flash device and performs a light emission operation, and that is configured so that a first light receiving element receives reflected light from a subject, and when the output of a light receiving circuit that integrates the amount of received light reaches a predetermined value, a light emission control circuit is operated to stop the emission of light from a first flash discharge tube due to the consumption of charging energy of a first main discharge capacitor. The main electronic flash device further comprises a second flash discharge tube that emits light by consuming charging energy of a second main discharge capacitor, and a flash unit that receives the light emitted by the second flash discharge tube and detects the emission of light from the main electronic flash device. a light response circuit which does not respond to light emitted from the second flash discharge tube but responds to light emitted from a first flash discharge tube of the main electronic flash device that is outside the wavelength range to which the film is sensitive, and generates a light emission signal and a light emission stop signal for the second flash discharge tube; a trigger circuit which receives the light emission signal to start the second flash discharge tube to emit light; and a light emission control circuit which receives the light emission stop signal to stop the light emission of the second flash discharge tube. (2) The electronic flash device for multiple flashes described in claim (1) of the utility model registration, in which the photoresponsive circuit comprises a second optical filter that passes light in the infrared region outside the wavelength range of light converted by the first optical filter, a second light receiving element that receives light in response to the light that has passed through the second optical filter, a circuit that generates a light emission signal in response to the light receiving operation of the second light receiving element, and a circuit that generates a light emission stop signal when no light is received by the second light receiving element. (3) The electronic flash device for multiple flashes described in claim (1) of the utility model registration, in which the photoresponsive circuit comprises a circuit that generates a light emission signal in response to the light receiving operation of the second light receiving element to the second light receiving element that receives light in the infrared region outside the wavelength range converted by the first optical filter, and a circuit that generates a light emission stop signal when no light is received by the second light receiving element.