Camera with automatic flash function and method for controlling the same

A camera having an automatic flash function, comprising:

• a plurality of switches including a power switch, a first step release switch, a second step release switch, and a photographing mode conversion switch;
• first means for measuring a distance with respect to an object to be photographed and for producing a signal corresponding to the measured distance when the first step release switch is activated;
• second means for measuring an ambient brightness surrounding the object and for producing a signal corresponding to the measured brightness when the first step release switch is activated;
• a shutter for being operated when the second step release switch is activated;
• a strobe for emitting a flash with a first predetermined amount of illumination to supplement any existing illumination on the object when the brightness measured by the second means is below a second predetermined amount of brightness;
• a microcontroller, the microcontroller including:
• means for charging the strobe when power is applied to the camera;
• means for receiving the measured distance and brightness signals respectively from the first and second measuring means when the first step release switch is activated;
• means for determining whether the measured distance and the ambient brightness are within a range for the strobe to be emitted in accordance with the measured signals to obtain a photograph with a suitable exposure;
• means for determining a charge state of the strobe when the measured distance and the ambient brightness are within-the range for the strobe to be emitted;
• means for comparing a present charge state of the strobe to a predetermined minimum charge voltage when the strobe is not completely charged;
• means, responsive to the comparing means, for determining whether a photograph of the object can be taken at the distance from the object and at the present charge state;
• means for determining a first duration of the flash from the strobe in accordance with the measured distance when the strobe is completely charged and for calculating a second duration of the flash from the strobe when the photograph can be taken and the strobe is not completely charged;
• means for driving the shutter when the second step release switch is activated;
• and
• means for emitting the strobe for one of the first and second calculated durations of the flash.

A method for controlling a camera having an automatic flash function with a strobe and a shutter, comprising the steps of:

• charging the strobe when power is applied to the camera;
• measuring a distance from the camera to an object to be photographed;
• measuring an ambient brightness surrounding the object;
• determining whether the strobe should be used in accordance with the measured distance and brightness to obtain a photograph with a suitable exposure;
• checking a charge state of the strobe when it is determined that the strobe should be used;
• comparing a present charge state of the strobe and a predetermined minimum charge voltage when the strobe is not completely charged;
• setting a duration for a flash of the strobe when the photograph can be taken in the present charge state;
• and
• energizing the strobe for the set duration when the camera is activated.

A method for controlling a camera having an automatic flash function, the camera including a strobe, a first step release switch, and a second step release switch, the method comprising steps of:

• applying power to the camera;
• charging the strobe when the power is applied to the camera;
• measuring a distance from an object to be photographed;
• measuring an ambient brightness surrounding the object;
• calculating an exposure amount in response to the distance measuring and brightness measuring steps when the first step release switch is activated;
• determining whether the strobe should be used in accordance with the measured distance and the measured brightness to obtain a photograph with a suitable exposure;
• checking a charge state of the strobe when the strobe should be used;
• comparing a present charge voltage and a predetermined minimum charge voltage when the strobe is not completely charged;
• calculating a brightness of the strobe in accordance with the measured distance and an F number in response to the comparing step;
• setting a duration for a flash of the strobe when the photograph can be taken in the present charge state;
• and
• carrying out the photography by flashing the strobe for the set duration when the second step release switch is activated.