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18
4-2. Flash Function
Flash Button
The default setting of the flash button is the AUTO position (no indication).
Each time the flash button is pressed, the flash mode changes as follows.
Each time the flash button is pressed, the flash mode changes as follows.
Forced flash
→
No flash
→
AUTO (no indication)
The following description explains operation of the forced flash mode.
When the main power is turned on in the “STILL” mode, the HI Controller
(IC603) detects its input from the flash button and sets the STB CHG signal
(pin 93) to “H”.
When the main power is turned on in the “STILL” mode, the HI Controller
(IC603) detects its input from the flash button and sets the STB CHG signal
(pin 93) to “H”.
Flash Unit
The STB CHG signal is sent to the charge circuit inside the flash unit that
charges the discharging capacity. The charge circuit inside the flash unit
has the high voltage oscillator that generates a high voltage (about 700 Vp-
p). The high voltage is rectified and charges the discharging capacitor up to
about 300 V. When the discharging capacitor is charged up to the specified
voltage, the XSTB FUL signal that is supplied from the flash unit is changed
from “H” to “L” informing the HI Controller (pin 32 of IC604) of the comple-
tion of charging.
charges the discharging capacity. The charge circuit inside the flash unit
has the high voltage oscillator that generates a high voltage (about 700 Vp-
p). The high voltage is rectified and charges the discharging capacitor up to
about 300 V. When the discharging capacitor is charged up to the specified
voltage, the XSTB FUL signal that is supplied from the flash unit is changed
from “H” to “L” informing the HI Controller (pin 32 of IC604) of the comple-
tion of charging.
HI Controller (IC603)
The flash LED has been blinking during charging, but is changed by the HI
Controller to turn on all the time.
Then the HI Controller waits that the shutter button is pressed. When the
shutter button is pressed, flashing is indicated by the STROB ON signal
from IC501.
Controller to turn on all the time.
Then the HI Controller waits that the shutter button is pressed. When the
shutter button is pressed, flashing is indicated by the STROB ON signal
from IC501.
When the flash unit receives the flashing signal (STROB ON), it turns on
the flash switch and activates the flash unit. The flash unit can adjust its
brightness. The reflection light that is returned from the subject flows the
current STROB A IN in the flash unit. The voltage is developed across a
resistor R513 through which the current STROB A IN flows so that the
detected voltage is fed back to IC501 (pin 77.) Turn-on time of the flash
unit is controlled in accordance with the detected voltage.
The detected voltage is also changed during the MACRO shooting by the
function of Q501.
the flash switch and activates the flash unit. The flash unit can adjust its
brightness. The reflection light that is returned from the subject flows the
current STROB A IN in the flash unit. The voltage is developed across a
resistor R513 through which the current STROB A IN flows so that the
detected voltage is fed back to IC501 (pin 77.) Turn-on time of the flash
unit is controlled in accordance with the detected voltage.
The detected voltage is also changed during the MACRO shooting by the
function of Q501.
The flash picture is stored in the CCD imager and the field video signal is
generated.
generated.
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