Display apparatus, mobile object and control apparatus

A control apparatus that controls an image display unit in which a display light emission unit having a light source emitting light forms an image using light emitted from the light source and emits display light corresponding to formed image, the emitted display light is deflected by a deflection unit, and the deflected display light is reflected toward a viewpoint of an observer by a narrow band reflection unit having characteristics of reflecting only light of a partial reflected wavelength range of a wavelength range of visible light and transmitting light of wavelengths other than the reflected wavelength range, and in which the narrow band reflection unit is composed such that the reflected wavelength range changes when an incidence angle of light which is incident on the narrow band reflection unit changes, the control apparatus comprising:

• a first control unit which controls the display light emission unit so as to form the image and cause the display light emission unit to emit the display light corresponding to the formed image;
• and
• a second control unit which changes an incidence angle at which the display light from the deflection unit is incident on the narrow band reflection unit, in accordance with change in a wavelength of the light emitted from the light source, wherein
• the second control unit changes the incidence angle such that a wavelength of the light emitted from the light source is included within the reflected wavelength range of the narrow band reflection unit.