Automatic color-temperature compensation device

An automatic color temperature compensation device for electronic cameras, comprising:

• (a) a first sensor having a first filter, said first filter adapted to pass a first color ray of light, said first sensor adapted to detect said first color ray and produce a first electrical signal in response to the detected first color ray;
• (b) a second sensor having a second filter, said second filter adapted to pass a second color ray of light, said second sensor adapted to detect said second color ray and produce a second electrical signal in response to the detected second color ray;
• (c) a third sensor having a third filter, said third filter adapted to pass a third color ray of light, said third sensor adapted to detect said third color ray and produce a third electrical signal in response to the detected third color ray;
• (d) a first ratio circuit adapted to receive and compare the first and second electrical signals and to produce a first ratio output in response to the ratio difference between said first and second electrical signals;
• (e) a second ratio circuit adapted to receive and compare the second and third electrical signals and to produce a second ratio output in response to the ratio difference between said second and third electrical signals;
• (f) a first comparator to receive the first ratio output and compare it with a first reference voltage, and to produce a first control voltage in response to the difference between said ratio output and said first reference voltage;
• (g) a second comparator to receive the second ratio output and compare it with a second reference voltage, and to produce a second control voltage in response to the difference between said second ratio output and said second reference voltage;
• and
• (h) a camera means including:
• a first signal means having a first filter for passing only red ray of light;
• a first pick-up tube capable of detecting the first color ray and producing a fourth electrical signal, a first gain controlling circuit adapted to adjust the gain of said fourth electrical signal;
• a second signal means having a second filter for passing a second color ray of light, a second pick-up tube capable of detecting the second color ray and producing a fifth electrical signal, and a second gain controlling circuit;
• and a third signal means having a third filter for passing a third color ray of light, a third pick-up tube capable of detecting the third color ray and producing a sixth electrical signal, a third gain controlling circuit adapted to adjust the gain of said sixth electrical signal;
• said first comparator being electrically connected to said first gain controlling circuit through a first switch means such that said first control voltage is delivered to said first gain controlling circuit for adjusting the gain of said fourth electrical signal, and said second comparator is electrically connected to said third gain controlling circuit through a second switch means such that said second control voltage is delivered to said third gain controlling circuit for adjusting the gain of said sixth electrical signal.