Light emitting unit, and lamp device having a radar device covered with light guide

A light emitting unit comprising:

• a light guide body that is placed in front of an electromagnetic wave radiation surface of a radar device and configured to cover at least a part of the electromagnetic wave radiation surface;
• and
• a light source that supplies light to the light guide body,
• wherein, in the case where a thickness of the light guide body is denoted by TG, and a wavelength of a radiated electromagnetic wave from the radar device in the light guide body is denoted by λd, TG is set such that TG=n×λd/2 (n being a natural number) is satisfied when a reflection loss of the light guide body with respect to the radiated electromagnetic wave is equal to or more than a transmission loss, and a reflection loss is −10 dB or less when a reflection loss is equal to or more than a transmission loss.

A lamp device having a lighting unit and a radar device that radiates an electromagnetic wave, and a light-transmitting cover, the lamp device comprising:

• a light guide body that is placed between the light-transmitting cover and an electromagnetic wave radiation surface of the radar device and covers at least a part of the electromagnetic wave radiation surface of the radar device;
• and
• a light source that supplies light to the light guide body,
• wherein a radiation surface correspondence area, which is an area of the light-transmitting cover overlapping the electromagnetic wave radiation surface as viewed from a direction perpendicular to the electromagnetic wave radiation surface, the light guide body, and the electromagnetic wave radiation surface are placed in such a manner as to be parallel to each other,
• the radiation surface correspondence area of the light-transmitting cover and the light guide body are configured to be sized and placed to cover the entire surface of the electromagnetic wave radiation surface as viewed from a direction perpendicular to the electromagnetic wave radiation surface,
• a thickness TK of the radiation surface correspondence area of the light-transmitting cover is set such that a reflection loss of the electromagnetic wave incident upon the radiation surface correspondence area of the light-transmitting cover is −10 dB or less,
• a thickness TG of the light guide body is set such that a reflection loss of the electromagnetic wave incident upon the light guide body is −10 dB or less, and
• an interval C1 between the radiation surface correspondence area and the light guide body is set such that a reflection loss of the electromagnetic wave incident upon the radiation surface correspondence area and the light guide body is −10 dB or less.