A signal generation apparatus, comprising: a first pulse generator configured to generate a first pulse to be supplied to a light source that irradiates light to a distance measurement target; a second pulse generator configured to generate a second pulse to be supplied to pixels that receive light reflected by the distance measurement target; wherein the first pulse generator and the second pulse generator each include: a first counter (310a, 310b), each first counter (310a, 310b) receiving the same clock signal, wherein the first counter of the first pulse generator is further configured to determine a phase of the first pulse according to a light source phase setting input to the first counter of the first pulse generator, and wherein the first counter of the second pulse generator is further configured to determine a phase of the second pulse according to a pixel phase setting input to the first counter of the second pulse generator; and a second counter (340a, 340b), each second counter (340a, 340b) being configured to determine a frequency of the first and the second pulse according to a modulation frequency setting which is common for the second counter of the first pulse generator and the second counter of the second pulse generator; and a switching section configured to: switch the modulation frequency setting of the first pulse generator and the second pulse generator within a predetermined period, and switch the setting for the second counter within the predetermined period. a first pulse generator configured to generate a first pulse to be supplied to a light source that irradiates light to a distance measurement target; a second pulse generator configured to generate a second pulse to be supplied to pixels that receive light reflected by the distance measurement target; wherein the first pulse generator and the second pulse generator each include: a first counter (310a, 310b), each first counter (310a, 310b) receiving the same clock signal, wherein the first counter of the first pulse generator is further configured to determine a phase of the first pulse according to a light source phase setting input to the first counter of the first pulse generator, and wherein the first counter of the second pulse generator is further configured to determine a phase of the second pulse according to a pixel phase setting input to the first counter of the second pulse generator; and a second counter (340a, 340b), each second counter (340a, 340b) being configured to determine a frequency of the first and the second pulse according to a modulation frequency setting which is common for the second counter of the first pulse generator and the second counter of the second pulse generator; and a first counter (310a, 310b), each first counter (310a, 310b) receiving the same clock signal, wherein the first counter of the first pulse generator is further configured to determine a phase of the first pulse according to a light source phase setting input to the first counter of the first pulse generator, and wherein the first counter of the second pulse generator is further configured to determine a phase of the second pulse according to a pixel phase setting input to the first counter of the second pulse generator; and a second counter (340a, 340b), each second counter (340a, 340b) being configured to determine a frequency of the first and the second pulse according to a modulation frequency setting which is common for the second counter of the first pulse generator and the second counter of the second pulse generator; and a switching section configured to: switch the modulation frequency setting of the first pulse generator and the second pulse generator within a predetermined period, and switch the setting for the second counter within the predetermined period. switch the modulation frequency setting of the first pulse generator and the second pulse generator within a predetermined period, and switch the setting for the second counter within the predetermined period.