A light projection device (1, 301, 401, 501, 701) comprising: a plurality of excitation light sources that emit excitation light; a light collection member; a fluorescent member (22, 222); a control portion that controls outputs of the excitation light sources; and a light projection member that projects light emitted from the fluorescent member (22, 222), characterized in that the light collection member includes a plurality of light guide portions (121, 122, 123, 124), each including a light entrance surface (121a, 122a, 123a, 124a) through which the excitation light enters the light guide portion and a light emission surface (121b, 122b, 123b, 124b) through which the excitation light is emitted toward the fluorescent member (22, 222), the light emission surface (121b, 122b, 123b, 124b) has a smaller area than the light entrance surface (121a, 122a, 123a, 124a), the excitation light sources are arranged opposite the light entrance surfaces (121a, 122a, 123a, 124a), the fluorescent member is arranged in a region including a focus (F23a, F23) of the light projecting member and includes a plurality of application regions (S121, S122, S123, S124, S222) to which the excitation light is applied, each of the application regions (S121, S122, S123, S124, S222) is specified by a shape of the light emission surface (121b, 122b, 123b, 124b) of the corresponding light guide portion (121, 122, 123, 124), and the control portion controls the outputs of the excitation light sources so as to individually control excitation states of the application regions to change a light projection pattern of the light projected from the light projection member. a plurality of excitation light sources that emit excitation light; a light collection member; a fluorescent member (22, 222); a control portion that controls outputs of the excitation light sources; and a light projection member that projects light emitted from the fluorescent member (22, 222), characterized in that the light collection member includes a plurality of light guide portions (121, 122, 123, 124), each including a light entrance surface (121a, 122a, 123a, 124a) through which the excitation light enters the light guide portion and a light emission surface (121b, 122b, 123b, 124b) through which the excitation light is emitted toward the fluorescent member (22, 222), the light emission surface (121b, 122b, 123b, 124b) has a smaller area than the light entrance surface (121a, 122a, 123a, 124a), the excitation light sources are arranged opposite the light entrance surfaces (121a, 122a, 123a, 124a), the fluorescent member is arranged in a region including a focus (F23a, F23) of the light projecting member and includes a plurality of application regions (S121, S122, S123, S124, S222) to which the excitation light is applied, each of the application regions (S121, S122, S123, S124, S222) is specified by a shape of the light emission surface (121b, 122b, 123b, 124b) of the corresponding light guide portion (121, 122, 123, 124), and the control portion controls the outputs of the excitation light sources so as to individually control excitation states of the application regions to change a light projection pattern of the light projected from the light projection member.