Microparticle analysis apparatus and microparticle analysis method
There is provided a microparticle analysis apparatus including a light detection unit configured to detect forward-scattered light generated from a microparticle that is an analysis target. The light detection unit includes a circuit having a high-pass filter that removes low frequency noise included in light entering the light detection unit and switches to the high-pass filter according to a predetermined frequency of the forward-scattered light.
1. A microparticle analysis apparatus comprising:
a light detection unit configured to detect forward-scattered light generated from a microparticle that is an analysis target,
wherein the light detection unit includes:
a high-pass filter that removes low frequency noise included in the forward-scattered light entering the light detection unit; and
a switching element, wherein the switching element is configured to selectively connect and disconnect the high-pass filter according to a predetermined frequency of the forward-scattered light.
2. The microparticle analysis apparatus according to claim 1 , wherein the light detection unit selectively connects and disconnects the high-pass filter when the predetermined frequency is equal to or higher than 200 kHz.
3. The microparticle analysis apparatus according to claim 2 , wherein the high-pass filter removes low frequency noise, included in leakage light, which avoids a zero-order light removal unit arranged between the microparticle and the light detection unit and which enters into the light detection unit.
4. The microparticle analysis apparatus according to claim 3 , wherein the high-pass filter removes noise of a frequency lower than 2 kHz.
5. The microparticle analysis apparatus according to claim 4 , further comprising
a first channel directly connected from an input side to an output side and a second channel having the high-pass filter,
wherein the first channel directly connected and the second channel having the high-pass filter are connected in parallel.
6. The microparticle analysis apparatus according to claim 5 ,
wherein the switching element performs switching to selectively connect and disconnect one of the first channel directly connected and the second channel having the high-pass filter.
7. The microparticle analysis apparatus according to claim 6 , further comprising
an amplifier configured to amplify a detection signal of the forward-scattered light.
8. A microparticle analysis method comprising:
removing low frequency noise included in light, entering a light detection unit, in a high-pass filter;
switching, by a switching element, to selectively connect and disconnect the high-pass filter according to a predetermined frequency of forward-scattered light generated from a microparticle that is an analysis target to analyze the microparticle.
9. The microparticle analysis apparatus according to claim 1 , wherein the high-pass filter is selectively connected when frequency of the forward-scattered light is greater than a first threshold and signal output level of the forward-scattered light is lesser than a second threshold.