Spatial frequency reproducing apparatus and optical distance measuring apparatus

A spatial frequency reproducing apparatus, comprising:

• a light source irradiating a light, which is irradiated convergently or irradiated in parallel, to an object under measurement;
• a first light processing member located on an irradiation optical axis of the convergent irradiation or the parallel irradiation and receiving and processing a luminous flux emitted from the object under measurement;
• a first photo detector having at least two divided photo detectors which receive lights of respective side portions with the irradiation optical axis being interposed therebetween within a transmitted light from the first light processing member;
• a pair of second light processing members each located on a tilted optical axis having a tilt with respect to the irradiation optical axis on one of light receiving sides of the divided photo detectors of the first photo detector, and receiving and processing a luminous flux emitted from the object under measurement and making the luminous flux and a luminous flux emitted from the first light processing member interfere with each other;
• a pair of second photo detectors receiving the luminous fluxes made to interfere by the pair of second light processing members;
• and
• an output summation/difference detection unit amplifying respective electrical signals photoelectrically converted by the two divided photo detectors while varying a degree of amplification according to frequencies of the electrical signals and amplifying respective electrical signals photoelectrically converted by the pair of second photo detectors while varying a degree of amplification according to frequencies of the electrical signals, and detecting an output summation or an output difference between outputs of the amplified electrical signals of the two divided photo detectors and an output summation or an output difference between outputs of the amplified electrical signals of the pair of second photo detectors.

A spatial frequency reproducing apparatus, comprising:

• a light source irradiating a light, which is irradiated convergently or irradiated in parallel, to an object under measurement;
• a first optical element located on a tilted optical axis having a tilt with respect to an irradiation optical axis of the convergent irradiation or the parallel irradiation and making two luminous fluxes interfere with each other;
• a plurality of first photo detectors each detecting the luminous fluxes made to interfere by the first optical element;
• a second optical element located on a tilted optical axis having a tilt reverse to that of the first optical element with respect to an irradiation optical axis of the convergent irradiation or the parallel irradiation and making two luminous fluxes interfere with each other;
• a plurality of second photo detectors each detecting the luminous fluxes made to interfere by the second optical element;
• and
• an output summation/difference detection unit amplifying respective electrical signals photoelectrically converted by the plurality of first photo detectors while varying a degree of amplification according to frequencies of the electrical signals and amplifying respective electrical signals photoelectrically converted by the plurality of second photo detectors while varying a degree of amplification according to frequencies of the electrical signals, and detecting an output value of a summation or a difference between an arbitrary light receiving output of the plurality of first photo detectors and an arbitrary light receiving output of the plurality of second photo detectors.