什么是光通量物理教科书上把光源在单位时间内向周围空间发射能够让人看得见的那部分辐射能量的总和称为光通量,用符号Φ表示,单位叫做流明(lm)。光源在单位立体角ω里所产生的光通量叫做发光强度I,单位为坎德拉(cd)。如果一个光源在立体角ω内均匀地产生Φ个流明的光通 What is luminous flux Physical textbooks put the light source in unit time to the surrounding space that can be seen that part of the total radiation energy called luminous flux, with the symbol Φ that the unit is called lumens (lm). The luminous flux of the light source in the unit solid angle ω is called luminous intensity I in candela (cd). If a light source produces a uniform lumen of Φ lumen at a solid angle ω