PROBLEM TO BE SOLVED: To provide a light detection unit that enables efficient arrangements of elements by appropriately mounting a light receiving part and a light emitting part on a first substrate and a second substrate, and to provide a biological information detection device, etc.SOLUTION: A light detection unit includes a light emitting part 150 for emitting light to an object, a light receiving part 140 for receiving the light from the object, a first substrate 160 on which the light emitting part 150 is mounted, and a second substrate 161 on which the light receiving part 140 is mounted. When the height of the first substrate 160 from a reference surface set opposite to the object with respect to the first substrate 160 is represented as h1, and the height of the second substrate 161 from the reference surface is represented as h2, h2 is greater than h1.COPYRIGHT: (C)2016,JPO&INPIT【課題】第1,第2の基板のそれぞれに対して受光部と発光部を適切に実装することで、素子の効率的な配置等を可能にする光検出ユニット及び生体情報検出装置等を提供する。【解決手段】光検出ユニットは、対象物に対して光を射出する発光部150と、対象物からの光を受光する受光部140と、発光部150が実装される第1の基板160と、受光部140が実装される第2の基板161を含み、第1の基板160に対して対象物とは反対側に設定された基準面からの、第1の基板160の高さをh1とし、基準面からの第2の基板161の高さをh2とした場合に、h2>h1となる。【選択図】図3
