Apparatus for analyzing particle images

Claim 2

Apparatus for analyzing particle images, comprising: a flow cell (24) for a sheath flow of a sample liquid containing particles; a first light source (10); a first optical filter (18) for obtaining fluorescence excitation light of a specific wavelength from the light emitted from the first light source (10); a photo detector (38) for detecting fluorescence emitted from a particle in a direction different to the direction of transmission of the fluorescence excitation light through the flow cell (24); a second light source (12) for emitting a pulse of light for producing an image of the particle (43); image pickup means (32) for picking up the image of the particle (43) produced by the second light source (12); particle detection judging means (40) for processing a fluorescent signal from the photo detector (38) to judge whether a target particle has been detected, and for issuing a trigger signal for activating the second light source (12) when it is judged that a target particle has been detected; a dichroic mirror (20) disposed so as to combine the optical paths of the light from the first and second light sources (10, 12) to irradiate a region of the flow cell (24); a second optical filter (28) disposed between the flow cell (24) and the image pickup means (32) for blocking off the fluorescence excitation light that has been transmitted through the flow cell (24); a third optical filter (29) disposed between the flow cell (24) and the photo detector (38) for blocking off the fluorescence excitation light; a shutter (34) disposed between the third optical filter (29) and the photo detector (38), for transmitting or blocking off light, the shutter being arranged to be closed while the second light source (12) is emitting light; and a slit (36) disposed between the shutter (34) and the photo detector (38) so as to form a sensing region (42) across the flow of particles in an image pickup region (44) of the image pickup means (32) in the flow cell (24).

Claim 3

Apparatus for analyzing particle images, comprising: a flow cell (24) for a sheath flow of a sample liquid containing particles; a first light source (10); an optical filter (18) for obtaining fluorescence excitation light of a specific wavelength from the light emitted from the first light source (10); a photo detector (38) for detecting fluorescence emitted from a particle (43) irradiated with the fluorescence excitation light; a second light source (12) for emitting a pulse of light for producing an image of the particle (43); image pickup means (32) for picking up the image of the particle (43) produced by the second light source (12); particle detection judging means (40) for processing a fluorescent signal from the photo detector (38) to judge whether a target particle has been detected, and for issuing a trigger signal for activating the second light source (12) when it is judged that a target particle has been detected; a dichroic mirror (21) disposed so as to receive from the flow cell (24) light produced by the second light source (12) that has been transmitted through the flow cell and to direct towards the flow cell the fluorescent excitation light; a half mirror (30) for dividing into first and second parts the light received from the flow cell (24) via the dichroic mirror (21), and for directing the first part towards the photo detector (38) and the second part towards the image pickup means (32); a shutter (34) disposed between the half mirror (30) and the photo detector (38), for transmitting or blocking off light, the shutter being arranged to be closed while the second light source (12) is emitting light; and a slit (36) disposed between the shutter (34) and the photo detector (38), so as to form a sensing region (42) across the flow of particles in an image pickup region (44) of the image pickup means (32) in the flow cell (24).

Claim 4

Apparatus for analyzing particle images, comprising: a flow cell (24) for a sheath flow of a sample liquid containing particles; a first light source (10); a first optical filter (18) for obtaining fluorescence excitation light of a specific wavelength from the light emitted from the first light source (10); a photo detector (38) for detecting fluorescence emitted from a particle (43) irradiated with the fluorescence excitation light; a second light source (12) for emitting a pulse of light for producing an image of the particle (43); image pickup means (32) for picking up the image of the particle (43) produced by the second light source (12); particle detection judging means (40) for processing a fluorescent signal from the photo detector (38) to judge whether a target particle has been detected, and for issuing a trigger signal for activating the second light source (12) when it is judged that a target particle has been detected; a second optical filter (28) disposed between the flow cell (24) and the photo detector (38) for blocking off the fluorescence excitation light; a shutter (34) disposed between the optical filter (28) and the photo detector (38), for transmitting or blocking off light, the shutter being arranged to be closed while the second light source (12) is emitting light; and a slit (36) disposed between the shutter (34) and the photo detector (38) so as to form a sensing region (42) across the flow of particles in an image pickup region (44) of the image pickup means (32) in the flow cell (24); wherein a first optical axis running from the first light source (10) to the photo detector (38) is separate from a second optical axis running from the second light source (12) to the image pickup means (32), and the first and second optical axes cross each other in the flow cell (24).

Claim 5

Apparatus according to claim 1, 2, 3 or 4, wherein the shutter (34) is omitted and, instead, the photo detector has a gate function, with the gate being arranged to be closed while the second light source (12) is emitting light.

Claim 6

Apparatus according to claim 1, 2, 3, 4 or 5, wherein the first light source (10) is arranged to emit light continuously, the second light source (12) is arranged to emit a pulse of white light and the image pickup means (32) is arranged to pick up a still image of the particle (43).

Claim 8

A method according to claim 7, wherein the particle sensing region (42) is located in the image pickup region (44) and is shorter, in the flow direction of the particles, than the image pickup region (44).

Claim 9

A method according to claim 8, wherein the lateral edges of the particle sensing region (42) are substantially coincident with the lateral edges of the image pickup region (44).

Claim 10

A method according to claim 7, 8 or 9, wherein the particle sensing region (42) is continuously irradiated with the fluoresence excitation light, and the sample liquid passes through the flow cell (24) as a sheath flow.