Vehicular lighting device

A vehicular lighting device comprising:

• a light source;
• a photosensor structured to receive light from the light source;
• a preamplifier structured to amplify an output of the photosensor, so as to generate a detection signal that indicates an amount of received light;
• and
• a lighting circuit structured to drive the light source based on at least the output of the preamplifier;
• wherein
• the photosensor and the preamplifier are mounted on a single sub-base member that is separate from a base member on which the lighting circuit is mounted, and
• the sub-base member and the lighting circuit are coupled via a signal line via which a signal that corresponds to the output of the preamplifier is transmitted, and via a power supply line via which a power supply voltage is supplied from the lighting circuit to the sub-base member.

A vehicular lighting device comprising:

• a light source furnished with a laser diode structured to emit excitation light and a phosphor structured to emit fluorescent light by undergoing excition by the excitation light, and that is structured to generate white output light containing the excitation light and fluorescent light spectra;
• a lighting circuit structured to drive the light source;
• a first photosensor structured to be sensitive to the excitation light's wavelength and to be substantially insensitive to the fluorescent light's wavelength, and to receive a part of the output light so as to generate a first current that corresponds to an amount of received light;
• a second photosensor structured to be sensitive to the fluorescent light's wavelength, to be substantially insensitive to the excitation light's wavelength, and to receive a part of the output light so as to generate a second current that corresponds to an amount of received light;
• a first preamplifier comprising a first operational amplifier and a first resistor arranged in a path of the first current, and structured to output a first detection signal that corresponds to a voltage drop across the first resistor;
• a second preamplifier comprising a second operational amplifier and a second resistor arranged in a path of the second current, and structured to output a second detection signal that corresponds to a voltage drop across the second resistor;
• and
• a judgement unit structured to judge the presence or absence of an abnormality in the light source based on the first detection signal and the second detection signal;
• wherein
• the first photosensor, the second photosensor, the first preamplifier, and the second preamplifier are mounted on a single sub-base member that is separate from a base member on which the lighting circuit is mounted.