Analysis threshold generation device and analysis threshold generation method

An analysis threshold generation device comprising:

• an optical pickup configured to irradiate, with an irradiation light, an analysis substrate of an optical disc, the analysis substrate of the optical disc having a surface to which a detection target substance and a particle bound to the detection target substance are fixed, and receive a reflection light of the irradiation light from the analysis substrate to generate a light reception level signal;
• a threshold calculation unit configured to generate a pair of thresholds for a pulse width of a pulse included in the light reception level signal or a pair of thresholds for a pulse amplitude of the pulse, the pair of thresholds for the pulse width including a pulse width upper-limit time which is a threshold time of the pulse width on an upper limit side and a pulse width lower-limit time which is a threshold time of the pulse width on a lower limit side, and the pair of thresholds for the pulse amplitude including an amplitude upper-limit voltage which is a threshold voltage of the pulse amplitude on an upper limit side and an amplitude lower-limit voltage which is a threshold voltage of the pulse amplitude on a lower limit side;
• a pulse determination unit configured to determine whether the pulse width is present within a range of the pair of thresholds for the pulse width or determine whether the pulse amplitude is present within a range of the pair of thresholds for the pulse amplitude;
• a pulse count unit configured to count the pulse determined to be present within the range of the generated pair of thresholds by the pulse determination unit, and output a count value of the pulse counted;
• a threshold correction unit configured to generate a pair of thresholds used for analysis in accordance with the pair of thresholds generated by the threshold calculation unit and the count value output from the pulse count unit;
• and
• a drive controller configured to control a position of the optical pickup so as to repeatedly measure a same position every time at least one of the pair of thresholds is changed by the threshold calculation unit,
• wherein the drive controller is configured to control the optical pickup so as to move the optical pickup to a measurement start position in order to repeatedly measure the same position every time at least one of the pair of thresholds is changed by the threshold calculation unit, and
• wherein the threshold calculation unit is configured to repeatedly generate a new pair of thresholds in which at least one of the pair of thresholds is changed every time the pulse count unit counts the pulse until reaching a predetermined value.