Electronic flash device and camera having the same
View Patent ↗An electronic flash device and a camera which can smoothly display a video even though preliminary emission for red-eye reduction in photographing the video are obtained. A timing generator generates a preliminary emission signal such that preliminary emission for red-eye reduction by a light emitting tube is performed in a period of operation of an electronic shutter arranged in an interline CCD to input the preliminary emission signal to a trigger circuit. The timing generator sets a period in which the preliminary emission signal is set at an active level as a period corresponding to a cycle between the edge of a pulse of a transfer gate signal serving as for transferring signal charges from a light-receiving element of the CCD to a vertical transfer path and the edge of a pulse of an overflow drain signal representing a timing at which excess charges are drained by an overflow drain of the CCD.
1. An electronic flash device which is used in a camera for performing photographing by an image pickup operation performed by a charge coupled device having an electronic shutter, an overflow drain and a light-receiving device, and which irradiates auxiliary light on an object if necessary in photographing by the camera, the camera having a timing generator for generating timing signals, comprising:
a light-emitting unit for emitting light to be irradiated on an object; and
an emission control unit for controlling the light-emitting unit such that preliminary emission for red-eye reduction for constricting pupils of a person is performed in a period of operation of the electronic shutter, wherein
the timing generator generates a charge transfer signal, an overflow drain signal and a vertical sync signal,
the charge transfer signal and the overflow drain signal are generated by the timing generator in synchronization with the vertical sync signal,
the emission control unit controls the light-emitting unit in synchronization with the charge transfer signal, and the overflow drain signal,
the change transfer signal is used for transferring signal charges from the light-receiving device to a vertical transfer path, and
the overflow drain signal controls draining of excess charges by the overflow drain.
2. The electronic flash device according to claim 1 , wherein the charge coupled device includes an interline charge coupled device (CCD).
3. The electronic flash device according to claim 1 , wherein the charge coupled device includes a frame transfer charge coupled device.
4. A camera comprising:
an electronic flash device, said electronic flash device including a light-emitting unit for emitting light to be irradiated on an object and an emission control unit for controlling the light-emitting unit such that preliminary emission for red-eye reduction for constricting pupils of a person is performed in a period of operation of the electronic shutter;
a charge coupled device for image pickup having an electronic shutter, an overflow drain and a light-receiving device; and
a signal generating unit for generating a drive signal for driving at least the charge coupled device, wherein
the signal generating unit generates a charge transfer signal, an overflow drain signal and a vertical sync signal,
the charge transfer signal and the overflow drain signal are generated by the signal generating unit in synchronization with the vertical sync signal,
the emission control unit of the electronic flash device is included in the signal generating unit and controls the light-emitting unit in synchronization with the charge transfer signal and the overflow drain signal,
the change transfer signal is used for transferring signal charges from the light-receiving device to a vertical transfer path, and
the overflow drain signal controls draining of excess charges by the overflow drain.
5. The camera according to claim 4 , wherein the charge coupled device includes an interline charge coupled device.
6. The camera according to claim 4 , wherein the charge coupled device includes a frame transfer charge coupled device.
7. The camera according to claim 4 , wherein the drive signal includes a charge transfer signal used for driving the charge coupled device.
8. A camera connectable to an electronic flash device that includes a light-emitting unit for emitting light to be irradiated on an object, the camera comprising:
a charge coupled device for image pickup having an electronic shutter, an overflow drain and a light-receiving device;
an emission control unit for controlling the light-emitting unit of connected electronic flash such that preliminary emission for red-eye reduction for constricting pupils of a person is performed in a period of operation of the electronic shutter; and
a signal generating unit for generating a drive signal for driving at least the charge coupled device, wherein
the signal generating unit generates a charge transfer signal, an overflow drain signal and a vertical sync signal,
the charge transfer signal and the overflow drain signal are generated by the signal generating unit in synchronization with the vertical sync signal,
the emission control unit of the electronic flash device is included in the signal generating unit and controls the light-emitting unit in synchronization with the charge transfer signal and the overflow drain signal,
the change transfer signal is used for transferring signal charges from the light-receiving device to a vertical transfer path, and
the overflow drain signal controls draining of excess charges by the overflow drain.
9. A method of controlling a light-emitting unit of an electronic flash which is used with a camera for performing photographing by an image pickup operation performed by a charge coupled device having an electronic shutter, an overflow drain and a light-receiving device, and which irradiates auxiliary light on an object if necessary in photographing by the camera, the camera having a timing generator for generating timing signals, the method comprising:
controlling the light-emitting unit such that preliminary emission for red-eye reduction for constricting pupils of a person is performed in a period of operation of the electronic shutter, said controlling includes controlling the light-emitting unit in synchronization with a charge transfer signal and an overflow drain signal, wherein
the timing generator generates the charge transfer signal, the overflow drain signal and a vertical sync signal,
the charge transfer signal and the overflow drain signal are generated by the timing generator in synchronization with the vertical sync signal,
the change transfer signal is used for transferring signal charges from the light-receiving device to a vertical transfer path, and
the overflow drain signal controls draining of excess charges by the overflow drain.