Image display apparatus and control method

1. An image display apparatus, comprising: a light source; at least one light modulation device configured: to modulate light from the light source, and to emit a modulated light beam; and a sensor configured: to receive diffracted light of the modulated light beam emitted from the at least one light modulation device, and to measure intensity of the modulated light beam, wherein the light source is capable of emitting the light containing red light, green light, and blue light, the at least one light modulation device includes three light modulation devices, the three light modulation devices being configured to modulate the red light, the green light, and the blue light, respectively, the image display apparatus further comprises a synthesizer, the synthesizer being configured to synthesize red modulated light, green modulated light, and blue modulated light modulated by the three light modulation devices, the sensor is configured: to receive the diffracted light of the modulated light beam synthesized by the synthesizer, and to measure intensity of the red modulated light, the green modulated light, and the blue modulated light, and the sensor includes: a plurality of sensor devices capable of measuring intensity of incident light, and a plurality of filters arranged on the plurality of sensor devices, respectively, the plurality of filters being configured to transmit light having a predetermined wavelength band.

2. The image display apparatus according to claim 1 , wherein the sensor is arranged on a light path of the diffracted light of the modulated light beam, the diffracted light of the modulated light beam having a predetermined order.

3. The image display apparatus according to claim 1 , wherein the at least one light modulation device includes a plurality of two-dimensionally arranged pixels, the plurality of two-dimensionally arranged pixels forming a periodic structure, the periodic structure being configured to generate the diffracted light of the modulated light beam.

4. The image display apparatus according to claim 1 , further comprising: a projector configured to project synthesized incident light, wherein the sensor is configured to receive diffracted light failing to enter the projector out of the diffracted light of the modulated light beam.

5. The image display apparatus according to claim 4 , wherein light from the light source enters the at least one light modulation device approximately perpendicularly, and the sensor is configured to receive diffracted light having a smallest absolute value of an order out of the diffracted light failing to enter the projector.

6. The image display apparatus according to claim 1 , wherein the synthesizer includes an emitter surface configured to emit a synthesized light beam, and the sensor is arranged in a vicinity of the emitter surface.

7. The image display apparatus according to claim 1 , wherein the plurality of filters include three kinds of filters, the three kinds of filters being: first filters configured to transmit light having a red wavelength band, second filters configured to transmit light having a green wavelength band, and third filters configured to transmit light having a blue wavelength band, the plurality of sensor devices are two-dimensionally arranged in a first direction and a second direction, the first direction and the second direction being orthogonal to each other, and in arrangement of the plurality of filters, a group of filters aligned in the first direction includes the three kinds of filters, and the three kinds of filters included in the group of filters are not adjacent to each other in the second direction.

8. The image display apparatus according to claim 7 , wherein the plurality of filters include fourth filters, the fourth filters being configured to transmit light having a noise component, the three kinds of filters being configured to transmit the light having the noise component, and in the arrangement of the plurality of filters, the group of filters aligned in the first direction includes the fourth filter, and the fourth filters are not adjacent to each other in the second direction.

9. The image display apparatus according to claim 1 , further comprising: a controller capable of controlling at least one of the light source and the at least one light modulation device based on the measured intensity of the modulated light beam.

10. A control method, comprising: receiving diffracted light of a modulated light beam emitted from a light modulation device, the light modulation device being configured to modulate light from a light source and to emit light; measuring intensity of the light; controlling at least one of the light source and the light modulation device based on the measured intensity of the light; emitting, using the light source, light containing red light, green light, and blue light; modulating, using three light modulation devices, the red light, the green light, and the blue light, respectively; synthesizing, using a synthesizer, red modulated light, green modulated light, and blue modulated light modulated by the three light modulation devices; receiving, using the sensor, the diffracted light of the modulated light beam synthesized by the synthesizer; measuring, using the sensor, intensity of the red modulated light, the green modulated light, and the blue modulated light; measuring, using the sensor, intensity of incident light; and transmitting, using a plurality of filters, light having a predetermined wavelength band.