Projector having blue light alleviating part

A projector, comprising:

• a light modulation part modulating light generated by a light source part;
• a video signal processing part processing a video signal to be input;
• and
• a projection optical system projecting the light modulated by said light modulation part onto an external projection target to obtain a projected video image, wherein
• said video signal processing part includes a blue light effect alleviating part alleviating effects of blue light on retinas, and
• in a case where among a red signal, a green signal, and a blue signal included in the video signal, only a ratio of said blue signal is high, said blue light effect alleviating part generates a blue light effect alleviating signal for controlling said light source part to reduce the brightness of said projected video image as a whole, wherein
• said blue light effect alleviating part includes:
• first, second, and third sum calculators calculating a sum of said red signals, a sum of said green signals, and a sum of said blue signals in individual pixels of video signals for one frame, respectively;
• first, second, and third multipliers multiplying output values of said first, second, and third sum calculators by values obtained by subtracting, as coefficients, a relative luminous efficiency at a wavelength of red light, a relative luminous efficiency at a wavelength of green light, and a relative luminous efficiency at a wavelength of blue light corresponding to three primary colors of light from one, respectively;
• a first adder adding output values of said first multiplier and said second multiplier;
• a second adder adding an output value of said first adder and an output value of said third multiplier;
• a divider dividing the output value of said first adder by an output value of said second adder;
• and
• a coefficient calculator outputting a first coefficient in a case where an output value of said divider is smaller than a specified value and outputting a second coefficient larger than said first coefficient in a case where the output value of said divider is equal to or larger than said specified value,
• said light source part includes:
• a red light source, a green light source, and a blue light source;
• and
• a first light source control driver outputting a first drive current for driving said red light source, a second light source control driver outputting a second drive current for driving said green light source, and a third light source control driver outputting a third drive current for driving said blue light source,
• said blue light effect alleviating signal is provided to said first to third light source control drivers, and
• said first to third light source control drivers output said first to third drive currents, respectively, at a duty ratio corresponding to said first or second coefficient based on said blue light effect alleviating signal.

A projector, comprising:

• a light modulation part modulating light generated by a light source part;
• a video signal processing part processing a video signal to be input;
• and
• a projection optical system projecting the light modulated by said light modulation part onto an external projection target to obtain a projected video image, wherein
• said video signal processing part includes a blue light effect alleviating part alleviating effects of blue light on retinas, and
• in a case where among a red signal, a green signal, and a blue signal included in the video signal, only a ratio of said blue signal is high, said blue light effect alleviating part generates a blue light effect alleviating signal for controlling said light source part to reduce the brightness of said projected video image as a whole,
• wherein said blue light effect alleviating part includes:
• first, second, and third sum calculators calculating a sum of said red signals, a sum of said green signals, and a sum of said blue signals in individual pixels of video signals for one frame, respectively;
• first, second, and third multipliers multiplying output values of said first, second, and third sum calculators by, as coefficients, a reciprocal of a relative luminous efficiency at a wavelength of red light, a reciprocal of a relative luminous efficiency at a wavelength of green light, and a reciprocal of a relative luminous efficiency at a wavelength of blue light corresponding to three primary colors of light, respectively;
• a first adder adding output values of said first multiplier and said second multiplier;
• a second adder adding an output value of said first adder and an output value of said third multiplier;
• a divider dividing the output value of said first adder by an output value of said second adder;
• and
• a coefficient calculator outputting a first coefficient in a case where an output value of said divider is smaller than a specified value and outputting a second coefficient larger than said first coefficient in a case where the output value of said divider is equal to or larger than said specified value,
• said light source part includes:
• a red light source, a green light source, and a blue light source;
• and
• a first light source control driver outputting a first drive current for driving said red light source, a second light source control driver outputting a second drive current for driving said green light source, and a third light source control driver outputting a third drive current for driving said blue light source,
• said blue light effect alleviating signal is provided to said first to third light source control drivers, and
• said first to third light source control drivers output said first to third drive currents, respectively, at a duty ratio corresponding to said first or second coefficient based on said blue light effect alleviating signal.