Spectrometry device, and spectrometry method

A spectrometry device comprising:

• an optical system configured to disperse measurement target light;
• a photodetector configured to detect a spectral image of the measurement target light dispersed by the optical system;
• and
• a storage unit, wherein
• the photodetector includes:
• a first light receiving unit including a plurality of first pixel columns arrayed in a horizontal direction parallel to a wavelength axis of the spectral image, each of the plurality of first pixel columns including a plurality of first pixels arrayed in a vertical direction perpendicular to the wavelength axis;
• a second light receiving unit juxtaposing with the first light receiving unit in the vertical direction and includes a plurality of second pixel columns arrayed in the horizontal direction, each of the plurality of second pixel columns including a plurality of second pixels arrayed in the vertical direction;
• a first vertical transfer unit configured to transfer a first charge accumulated in each of the plurality of first pixels by receiving the spectral image for a first exposure time in the first light receiving unit, for each of the plurality of first pixel columns in the vertical direction;
• a first horizontal transfer unit configured to transfer the first charge transferred by the first vertical transfer unit in the horizontal direction;
• a first amplifier configured to output a first electric signal corresponding to an amount of the first charge transferred by the first horizontal transfer unit;
• a second vertical transfer unit configured to transfer a second charge accumulated in each of the plurality of second pixels by receiving the spectral image for a second exposure time longer than the first exposure time in the second light receiving unit, for each of the plurality of second pixel columns in the vertical direction;
• a second horizontal transfer unit configured to transfer the second charge transferred by the second vertical transfer unit in the horizontal direction;
• and
• a second amplifier configured to output a second electric signal corresponding to an amount of the second charge transferred by the second horizontal transfer unit, and
• the storage unit
• stores a first correction coefficient for correcting the first electric signal to make a linearity characteristic of the first amplifier match with a reference linearity characteristic, and
• stores a second correction coefficient for correcting the second electric signal to make a linearity characteristic of the second amplifier match with the reference linearity characteristic.

A spectrometry method using a spectrometry device, the spectrometry device including:

• an optical system configured to disperse measurement target light;
• a photodetector configured to detect a spectral image of the measurement target light dispersed by the optical system;
• and
• an analysis unit configured to generate spectrum data of the measurement target light,
• the photodetector including:
• a first light receiving unit including a plurality of first pixel columns arrayed in a horizontal direction parallel to a wavelength axis of the spectral image, each of the plurality of first pixel columns including a plurality of first pixels arrayed in a vertical direction perpendicular to the wavelength axis;
• a second light receiving unit juxtaposing with the first light receiving unit in the vertical direction and includes a plurality of second pixel columns arrayed in the horizontal direction, each of the plurality of second pixel columns including a plurality of second pixels arrayed in the vertical direction;
• a first vertical transfer unit configured to transfer a first charge accumulated in each of the plurality of first pixels by receiving the spectral image for a first exposure time in the first light receiving unit, for each of the plurality of first pixel columns in the vertical direction;
• a first horizontal transfer unit configured to transfer the first charge transferred by the first vertical transfer unit in the horizontal direction;
• a first amplifier configured to output a first electric signal corresponding to an amount of the first charge transferred by the first horizontal transfer unit;
• a second vertical transfer unit configured to transfer a second charge accumulated in each of the plurality of second pixels by receiving the spectral image for a second exposure time longer than the first exposure time in the second light receiving unit, for each of the plurality of second pixel columns in the vertical direction;
• a second horizontal transfer unit configured to transfer the second charge transferred by the second vertical transfer unit in the horizontal direction;
• and
• a second amplifier configured to output a second electric signal corresponding to an amount of the second charge transferred by the second horizontal transfer unit,
• the spectrometry method comprising:
• a step of correcting the first electric signal to make a linearity characteristic of the first amplifier match with a reference linearity characteristic and correcting the second electric signal to make a linearity characteristic of the second amplifier match with the reference linearity characteristic;
• a step of generating first spectrum data based on the corrected first electric signal and generating second spectrum data based on the corrected second electric signal;
• and
• a step of generating the spectrum data of the measurement target light based on the first spectrum data and the second spectrum data.