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 only a ratio of a blue signal included in the video signal is high, said blue light effect alleviating part performs control to reduce the brightness of said projected video image as a whole by reducing signal values of said blue signal, a green signal, and a red signal, wherein said blue light effect alleviating part includes:
• first, second, and third sum calculators calculating a sum of said red signals, said green signals, and said blue signals in individual pixels of video signals for one frame;
• fourth, fifth, and sixth 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, respectively, from one;
• a first adder adding output values of said fourth multiplier and said fifth multiplier;
• a second adder adding an output value of said first adder and an output value of said sixth multiplier;
• a divider dividing the output value of said first adder by an output value of said second adder;
• 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;
• first, second, and third delay units outputting said red signal, said green signal, and said blue signal as a red delay signal, a green delay signal, and a blue delay signal, respectively, with delays of predetermined periods;
• and
• first, second, and third multipliers respectively multiplying said red delay signal, said green delay signal, and said blue delay signal by said first or second coefficient.

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 only a ratio of a blue signal included in the video signal is high, said blue light effect alleviating part performs control to reduce the brightness of said projected video image as a whole by reducing signal values of said blue signal, a green signal, and a red signal, wherein said blue light effect alleviating part includes:
• first, second, and third sum calculators calculating a sum of said red signal, said green signal, and said blue signal in individual pixels of the video signal for one frame;
• fourth, fifth, and sixth 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 fourth multiplier and said fifth multiplier;
• a second adder adding an output value of said first adder and an output value of said sixth multiplier;
• a divider dividing the output value of said first adder by an output value of said second adder;
• 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;
• first, second, and third delay units outputting said red signal, said green signal, and said blue signal as a red delay signal, a green delay signal, and a blue delay signal, respectively, with delays of predetermined periods;
• and
• first, second, and third multipliers respectively multiplying said red delay signal, said green delay signal, and said blue delay signal by said first or second coefficient.