Patent ID: 8659724

Claim:
A liquid crystal display device comprising: a first substrate; a second substrate located opposite the first substrate via a liquid crystal; a blue display element, a green display element, a red display element, a short-wavelength optical sensor, a red optical sensor, and an infrared optical sensor formed on a liquid crystal side surface of the first substrate; a color filter formed between the first substrate and the second substrate and comprising a blue filter, a green filter, a first red filter, a short-wavelength transmission filter, a second red filter, and an infrared transmission filter corresponding to the blue display element, the green display element, the red display element, the short-wavelength optical sensor, the red optical sensor, and the infrared optical sensor, respectively; and a calculating section which calculates a difference between a signal for incident light obtained by a first optical sensor and a signal for incident light obtained by a second optical sensor which is used for detecting the shortest wavelength range next to that of the first optical sensor, the first and second optical sensors being included in the plurality of optical sensors which measures the incident light via the color filter, wherein the first and second red filters have a 50% transmittance at an optical wavelength between 580 nm and 620 nm, and have a transmittance characteristic such that a transmittance is lower than the 50% transmittance when a wavelength is smaller than a wavelength corresponding to the 50% transmittance, and is higher than the 50% transmittance when the wavelength is larger than the wavelength corresponding to the 50% transmittance, and the first and second red filters are optically superimposed above the red display element and the red optical sensor, respectively, and the infrared transmission filter has a 50% transmittance at an optical wavelength between 650 nm and 720 nm, and has a transmittance characteristic such that a transmittance is lower than the 50% transmittance when a wavelength is smaller than a value corresponding to the 50% transmittance, and is higher than the 50% transmittance when the wavelength is larger than the value corresponding to the 50% transmittance, and the infrared transmission filter is optically superimposed above the infrared optical sensor.