JP4598554B2 - Photodetector - Google Patents

Description

  The present invention relates to a light detection device that detects a distribution of measurement light.

  Conventionally, cell measurement methods such as cytometry, and optical measurement using a laser microscope (LSM) or the like have been performed. In such a measurement field, a multi-channel laser light emitting device is used as an excitation light source to measure fluorescence emitted from an object to be measured on a slide glass, or to measure the wavelength distribution of the measurement light by spectroscopy. Has been done. In such optical measurement, a photodetector having a plurality of light detection channels is used in order to enable measurement light to be measured simultaneously in a plurality of channels. Also, in the medical field, as represented by a PET (Positron Emission Tomography) apparatus, in order to realize high spatial resolution, a multi-anode type photomultiplier tube having a plurality of subdivided anodes, A resolution scintillator or the like is used.

For example, the light detection device disclosed in Patent Document 1 separates measurement light in the same direction according to the wavelength, and detects the dispersed measurement light using a light receiving element. Further, in the spectroscopic measurement apparatus disclosed in Patent Document 2, a filter member is provided at a position corresponding to each channel on the light receiving surface of a multi-anode type photomultiplier tube. With such a configuration, spectroscopic measurement can be simultaneously performed in each channel of the photomultiplier tube. Patent Documents 3 and 4 describe a measuring apparatus that simultaneously irradiates a plurality of samples with a plurality of light sources and receives light transmitted through the sample with a plurality of light receiving elements.
JP 2004-144678 A JP 11-329339 A JP 11-37932 A Japanese Utility Model Publication No. 6-10856 JP-A-2-61611

  However, in the conventional detection apparatus, when the measurement light is received by a photodetector such as a light receiving element or a photomultiplier tube, the measurement lights are guided in parallel directions. In light measurement by such a detection device, it is necessary to increase the number of light detection channels in order to achieve high resolution, but if the light detection channel is subdivided, crosstalk between adjacent channels occurs. High-precision measurement becomes difficult.

  Accordingly, the present invention has been made in view of such problems, and provides a photodetection device that can sufficiently reduce crosstalk between adjacent channels even when the measurement light detection channels are multi-channeled. The purpose is to do.

In order to solve the above-described problems, a photodetection device according to the present invention is a photodetection device that detects a distribution of measurement light incident on an incident surface, and includes a plurality of photodetection channels arranged in at least a first direction. A first photodetector having one light receiving surface and a plurality of light detection channels arranged in at least a first direction and having a second light receiving surface facing substantially parallel to the first light receiving surface. Two light detectors, a plurality of light introduction units arranged in at least a first direction on the incident surface and introducing measurement light in a second direction substantially perpendicular to the first direction, and a first light receiving A plurality of light reflections disposed between the surface and the second light receiving surface, on the extension line in the second direction of the plurality of light introducing portions and reflecting the measurement light toward the corresponding separate light detection channels and a section, first and second photodetectors, respectively, first and A plurality of light detection channels that are two-dimensionally arranged in a direction substantially perpendicular to the first direction and the first direction along the two light receiving surfaces; Are two-dimensionally arranged in a first direction and a third direction substantially perpendicular to the first direction, and the plurality of light reflecting portions are alternately arranged along the first direction. It is formed so as to face the first light receiving surface side and the second light receiving surface side.

  According to such a light detection device, the measurement light is guided in a direction substantially perpendicular to the arrangement direction in a state of being arranged in one direction by passing through the light introducing portion, By being reflected by the light reflecting portion, the light is incident on the light detection channels of the first and second photodetectors alternately in the arrangement direction. At this time, the measurement light is reflected in a direction perpendicular to the arrangement direction and is incident on each light detection channel. Therefore, even if the measurement light is increased in number of channels in order to increase the resolution during measurement, the distance between the light detection channels on which each measurement light is incident is increased, thereby reducing crosstalk between the light detection channels. Is done. As a result, measurement light can be simultaneously detected by a plurality of channels, so that measurement time can be shortened.

Furthermore, when measuring the two-dimensional distribution of the measurement light, the distance in the first direction between the light detection channels on which the respective measurement light enters is increased, so that crosstalk between the light detection channels is reduced.

  Further, the plurality of light introducing portions introduce measurement light in a second direction substantially perpendicular to the third direction, and the plurality of light reflecting portions have an inclination angle of about 45 with respect to the second direction. It is also preferable that it is formed along the inclination direction of the inclined surface substantially parallel to the first direction. With such a configuration, when measuring a two-dimensional distribution of measurement light, each measurement light can be guided to different light detection channels. In addition, since the optical path length from the incident surface to the light receiving surface is substantially the same in each photodetector, the uniformity of measurement sensitivity between the photodetection channels can be improved.

  In addition, it is also preferable that the inclined surface on which the plurality of light reflecting portions are formed intersects in a straight line at the center position between the first light receiving surface and the second light receiving surface in the third direction. With such a configuration, since the optical path length from the incident surface to the light receiving surface is substantially the same between the two photodetectors, it is possible to further improve the uniformity of measurement sensitivity between the entire light detection channels.

  The first and second photodetectors are preferably multi-anode type photomultiplier tubes. If such a photodetector is provided, it is possible to simultaneously detect the measurement light of a plurality of channels with high sensitivity.

  Alternatively, the photodetection device of the present invention is a photodetection device that detects the distribution of measurement light incident on the incident surface, wherein the plurality of photodetection channels are substantially perpendicular to the first direction and the first direction. A first photodetector having a first light receiving surface that is two-dimensionally arranged in the direction, and a plurality of light detection channels are two-dimensionally arranged in the first direction and the second direction, A second photodetector having a second light-receiving surface facing substantially parallel to the first light-receiving surface; a third direction in which the plurality of light detection channels are perpendicular to the first and second light-receiving surfaces; A third photodetector having a third light receiving surface arranged two-dimensionally in the second direction, and a plurality of light detection channels arranged two-dimensionally in the third direction and the second direction. A fourth photodetector having a fourth light receiving surface facing substantially parallel to the third light receiving surface, and a first light incident surface. A plurality of light introductions in a region surrounded by the first to fourth light receiving surfaces and a plurality of light introduction parts that are two-dimensionally arranged in the direction and the third direction and introduce measurement light in the second direction A plurality of light reflecting portions arranged on an extension line in the second direction of the portion and reflecting the measurement light toward the corresponding different light detection channels, and the plurality of light reflecting portions include the first and third light reflecting portions. It is characterized by being formed so as to face different directions alternately along the direction.

  According to such a light detection device, the measurement light is guided in a direction substantially perpendicular to the incident surface in a state of being two-dimensionally arranged by passing through the light introducing portion, and the guided measurement light is By being reflected by the light reflecting portion, the light is alternately incident on the light detection channels of the separate light detectors in the two arrangement directions. At this time, the measurement light is incident in a direction perpendicular to the light receiving surface of the photodetector. Therefore, even if the measurement light is increased in number of channels in order to increase the resolution during measurement, the distance between the light detection channels on which each measurement light is incident is increased, thereby reducing crosstalk between the light detection channels. Is done. As a result, measurement light can be simultaneously detected by a plurality of channels, so that measurement time can be shortened.

  The plurality of light reflecting portions alternately reflect the measurement light toward the second light receiving surface and the measurement light toward the fourth light receiving surface along the third direction. The first light reflecting member formed with the light reflecting surface, the light reflecting surface that reflects the measurement light toward the first light receiving surface alternately along the third direction, and the third light receiving surface And a second light reflecting member formed with a light reflecting surface for reflecting the measurement light toward the measuring light, and the first light reflecting member and the second light reflecting member are alternately arranged in the first direction. It is preferable. In this case, it is easy to share the light reflecting members constituting the plurality of light reflecting portions, the manufacturing efficiency is improved, and the number of assembling steps is reduced.

  The plurality of light reflecting portions have an inclination angle of about 45 degrees with respect to the second direction and are formed along an inclination direction of an inclined surface substantially parallel to the first direction, and with respect to the second direction. It is preferable that the inclination angle is approximately 45 degrees, and the inclination angle is formed along the inclination direction of the inclined surface substantially parallel to the third direction. With such a configuration, when measuring a two-dimensional distribution of measurement light, each measurement light can be guided to different light detection channels. In addition, since the optical path length from the incident surface to the light receiving surface is substantially the same in each photodetector, the uniformity of measurement sensitivity between the photodetection channels can be improved.

  In addition, the inclined surface on which the plurality of light reflecting portions are formed intersects in a straight line at the center position between the first light receiving surface and the second light receiving surface in the third direction, and in the first direction. It is also preferable to intersect on a straight line at the center position between the third light receiving surface and the fourth light receiving surface. In this case, with this configuration, the optical path length from the incident surface to the light receiving surface is substantially the same among the four photodetectors, so that the uniformity of measurement sensitivity between the entire photodetection channels can be further improved. Can do.

  The first to fourth photodetectors are preferably multi-anode type photomultiplier tubes. If such a photodetector is provided, it is possible to simultaneously detect the measurement light of a plurality of channels with high sensitivity.

  The light source further includes an excitation light source that is provided opposite to the plurality of light introduction portions with the plurality of light reflection portions interposed therebetween, and that emits excitation light for exciting the measurement object in the second direction. It is also preferable that the unit has a dichroic mirror that transmits light in the wavelength band of excitation light and reflects light in the wavelength band of measurement light emitted from the measurement object. With this configuration, since the excitation light source is provided on the opposite side of the measurement object with the light reflecting portion interposed therebetween, the excitation light source is used as the optical path of the measurement light when measuring the distribution of light emitted from the measurement object. In addition, it is possible to prevent a complicated light guiding means for guiding the excitation light.

  According to the light detection apparatus of the present invention, even when the detection light detection channels are multi-channeled, crosstalk between adjacent channels can be sufficiently reduced.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, a preferred embodiment of a light detection device according to the invention will be described in detail with reference to the drawings. In the description of the drawings, the same or corresponding parts are denoted by the same reference numerals, and redundant description is omitted.

[First Embodiment]
FIG. 1 is a perspective view of a light detection device according to a first embodiment of the present invention, and FIG. 2 is an exploded perspective view of the light detection device of FIG. The light detection device 1 is a device for detecting a distribution for each wavelength band by splitting a plurality of measurement lights.

  As shown in FIGS. 1 and 2, the photodetecting device 1 includes multi-anode type photomultiplier tubes (photodetectors) 2 and 3. The photomultiplier tubes 2 and 3 have square columnar side tubes 4 and 5, respectively, and rectangular light incident plates formed of a light transmissive material on the side of the end portions of the side tubes 4 and 5, respectively. (Light receiving surfaces) 6, 7 are fixed in an airtight manner. Photoelectric surfaces are formed inside the light incident plates 6 and 7 along the surfaces of the light incident plates 6 and 7, and inside the side tubes 4 and 5, an electron multiplier and an electron multiplier are interposed. And anodes arranged in a two-dimensional matrix with 8 rows and 8 columns. Further, band pass filters 8 and 9 having substantially the same shape as the light incident plates 6 and 7 are fixed outside the light incident plates 6 and 7 so as to cover the light incident plates 6 and 7, respectively. The bandpass filters 8 and 9 are arranged in 4 rows and 4 columns at positions corresponding to the light shielding portions 8 a and 9 a formed in a flat plate shape with a light shielding material and the anodes arranged in a matrix in the side tubes 4 and 5. Filter units 8b and 9b that are provided at regular intervals in a matrix and transmit measurement light in a specific wavelength band. Here, assuming that the arrangement direction of the filter portions 8b and 9b formed in the bandpass filters 8 and 9 is the X axis and the Y axis, and the direction perpendicular to the XY plane is the Z axis, the anode is connected to the side tubes 4 and 5. They are arranged in a two-dimensional matrix of 8 rows and 8 columns on the internal XY plane. Further, 16 photodetecting channels are formed at every other position of these 64 anodes, that is, at positions corresponding to the filter portions 8b and 9b of the bandpass filters 8 and 9.

  The photomultiplier tubes 2 and 3 described above are provided at symmetrical positions so that the light incident plates 6 and 7 face each other substantially in parallel. Between the light incident plates 6 and 7, a rectangular parallelepiped-shaped reflector housing portion. 10 is fixed. An opening 15 is formed at the −Y direction side end of the reflector housing part 10, and a notch that is cut out in a rectangular shape on the + Z direction side surface and the −Z direction side surface of the opening 15, respectively. 11 and 12 are formed. Eight light reflecting plates 13 are accommodated in the notches 11 and 12.

  The light reflecting plate 13 is formed in a substantially right triangle shape so that the angle formed by the oblique side and the other two sides is about 45 degrees, and four light reflecting portions 14 made of a light reflective material are formed on the end surface on the oblique side. Are formed at equal intervals (see FIG. 3). The light reflecting plate 13 is accommodated in the notches 11 and 12 in a state where one side on the Y direction side is overlapped so that two sides other than the oblique side are parallel to the Z axis and the Y axis. At this time, as a result of the eight light reflecting plates 13 being overlapped so that the directions of the hypotenuses are staggered, the light reflecting portions 14 alternately face the light incident plate 6 and the light incident plate 7 along the X-axis direction. In addition, the inclination angle of the light reflecting portion 14 with respect to the Y axis and the Z axis is both about 45 degrees. The light reflecting portions 14 are arranged such that the filter portions 8b and 9b are positioned on the extended lines in the Z-axis direction of the respective light reflecting portions 14.

  A band-pass filter 16 having substantially the same shape as the opening 15 is fitted in the opening 15 of the reflector housing part 10. The band-pass filter 16 is two-dimensionally arranged in eight rows in the X direction and four rows in the Z direction on the light shielding portion 16a made of a light shielding material and an extension line of the light reflecting portion 14 in the -Y direction. And a filter unit 16b that transmits measurement light in a specific wavelength band.

Further, a flat plate-shaped spectroscopic plate (incident surface) 17 is fixed to the opening 15 with the band-pass filter 16 interposed therebetween. Four light input portions 18 are formed at equal intervals in the Z-axis direction on the end surface of the spectroscopic plate 17 on the −X direction side. By connecting an optical fiber or the like to the optical input unit 18, four measurement lights are simultaneously input in parallel. A dichroic mirror array 19 is provided in the spectroscopic plate 17 along the X direction from each light input unit 18. The dichroic mirror array 19 is composed of eight dichroic mirrors (light introducing portions) DM _{1 to} DM ₈ having different shortest wavelengths in the light transmission band, arranged in the order in which the shortest wavelengths gradually increase along the X direction. Yes, the measurement light incident in the X direction from the light input unit 18 is divided into different wavelength bands and reflected in the Y direction. The dichroic mirrors DM _{1 to} DM ₈ are provided so as to be positioned on an extension line in the −Y-axis direction of the light reflecting portion 14, and introduce measurement light toward the respective light reflecting portions 14 in the Y direction.

The measurement light detection operation in the light detection apparatus 1 configured as described above will be described by taking two optical paths as an example. As shown in FIGS. 2 and 4, the measurement light input to the X-direction from the light input section 18 and, at the same time is split by the dichroic mirror DM _8, it is reflected toward the Y direction (arrow L1). Dichroic measurement light reflected by the dichroic mirror DM ₈ is incident after passing through the filter unit 16b of the band-pass filter 16, the light reflecting portion 14 formed along the inclined surface S1 of the light reflection plate 13, the light reflecting portion 14, the light is reflected in the −Z direction toward the filter unit 9 b of the bandpass filter 9. Thereafter, the measurement light incident on the filter unit 9b is detected by the photodetection channel of the photomultiplier tube 3 facing the filter unit 9b.

On the other hand, is input from the same light input portion 18 in the X direction, measuring light split by the dichroic mirror DM ₇ is transmitted through the filter unit 16b of the band-pass filter 16, along the inclined surface S2 of the light reflection plate 13 Then, the light enters the light reflecting portion 14 formed (arrow L2). Thereafter, the measurement light is reflected in the Z direction toward the filter unit 8 b of the bandpass filter 8 by the light reflecting unit 14. Thus, the measurement light incident on the filter unit 8b is detected by the photodetection channel of the photomultiplier tube 2 facing the filter unit 8b.

Here, referring to FIG. 4, the inclined surface S1 and the inclined surface S2 of the light reflecting plate 13 intersect on a straight line C1 having substantially the same distance from the light incident plates 6 and 7, that is, the light incident plates 6 and 7. It intersects on a straight line at the center position. With the arrangement of the light incident plates 6 and 7, the optical path lengths from the positions of the dichroic mirrors DM _{1 to} DM ₈ corresponding to the four light input units 18 to the light incident plates 6 and 7 are made the same.

  The operational effects of the light detection device 1 described above will be described.

  According to the light detection device 1, the measurement light is guided in the Y direction in a state of being arranged in the X direction by passing through the dichroic mirror array 19 of the spectroscopic plate 17, and the guided measurement light is reflected by the light reflection unit 14. Are incident on the photodetection channels of the photomultiplier tube 2 and the photomultiplier tube 3 alternately in the X direction. At this time, the measurement light is incident on the light detection channel perpendicular to the arrangement direction (Z-axis direction). Therefore, even if the measurement light is increased in number of channels in order to increase the resolution during measurement, the distance between the light detection channels on which each measurement light is incident is increased, thereby reducing crosstalk between the light detection channels. Is done. As a result, measurement light can be simultaneously detected by a plurality of channels, so that measurement time can be shortened.

  The photomultiplier tubes 2 and 3 have a plurality of photodetection channels arranged two-dimensionally in the X direction and the Y direction along the respective light incident plates 6 and 7, and have a dichroic mirror array. 19 are two-dimensionally arranged in the X direction and the Z direction along the spectral plate 17. As a result, when measuring the two-dimensional distribution of the measurement light, the distance in the X direction between the light detection channels on which the respective measurement lights are incident is increased, so that crosstalk between the light detection channels is reduced.

  Further, since the light reflecting portion 14 has an inclination angle of about 45 degrees with respect to the Y axis and is formed along the inclination directions of the inclined surfaces S1 and S2 parallel to the X axis, the two-dimensional distribution of the measurement light can be obtained. In the measurement, each measurement light can be guided to a different light detection channel. Further, since the optical path lengths from the spectroscopic plate 17 to the light incident plates 6 and 7 are substantially the same in the respective photomultiplier tubes 2 and 3, the uniformity of measurement sensitivity between the photodetection channels can be improved. Furthermore, since the inclined surfaces S1 and S2 intersect on a straight line at the center position between the light incident plate 6 and the light incident plate 7, the optical path length from the spectroscopic plate 17 to the light incident plates 6 and 7 is 2. Since the two photomultiplier tubes are substantially the same, the uniformity of measurement sensitivity between the entire photodetection channels can be further enhanced.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. FIG. 5 is a perspective view of a photodetecting device according to a second embodiment of the present invention, and FIG. 6 is an exploded perspective view of the photodetecting device of FIG. The photodetector 31 according to the present embodiment is provided with four photomultiplier tubes, which are photodetectors, provided in a radial manner, the configuration of the light introducing unit, the arrangement of the light reflecting unit, and the excitation light source. This is different from the first embodiment.

  That is, in the photodetecting device 31, four multi-anode type photomultiplier tubes 32, 33, 34, and 35 are provided, and light incident plates are provided at the end portions of the side tubes 36, 37, 38, and 39, respectively. 40, 41, 42 and 43 are fixed in an airtight manner. In addition, outside the light incident plates 40, 41, 42, 43, band-pass filters 44, 45, 46, having filter sections 44b, 45b, 46b, 47b arranged in a matrix of 4 rows and 4 columns, respectively. 47 is fixed. The configurations of these photomultiplier tubes 32 to 35 are the same as the configurations of the photomultiplier tubes 2 and 3 described in the first embodiment. In the photomultiplier tubes 32 to 35, the light incident plate 40 and the light incident plate 41, and the light incident plate 42 and the light incident plate 43 face each other substantially in parallel. It arrange | positions radially so that the perpendicular | vertical line of the entrance plates 42 and 43 surface may orthogonally cross. Here, the arrangement direction of the photodetection channels of the photomultiplier tubes 32 and 33 is defined as the X direction and the Y direction, and the arrangement direction of the photodetection channels of the photomultiplier tubes 34 and 35 is defined as the Y direction and the Z direction.

  In a region surrounded by the light incident plates 40, 41, 42, 43, a rectangular parallelepiped reflector housing 48 is fixed. An opening 49 is formed at the end portion on the −Y direction side of the reflector housing portion 48, and a notch portion that is cut out in a rectangular shape on the + Z direction side surface and the −Z direction side surface of the opening portion 49, respectively. 50 and 51 are formed. Eight light reflecting plates (light reflecting members) 54 are accommodated in the notches 50 and 51. Further, on the + X direction side surface and the −X direction side surface of the reflector housing portion 48, open portions 52 and 53 for allowing measurement light to pass toward the photomultiplier tube 34 and the photomultiplier tube 35, respectively. Is formed.

  As shown in FIG. 7, the light reflecting plates 54a, 54b, 54c, and 54d have the same shape as the light reflecting plates 54e, 54f, 54g, and 54h, respectively. The light reflecting plates 54a to 54h are formed in a substantially right triangle shape so that the angle formed between the oblique side and the other two sides is about 45 degrees, and the four light reflecting portions 55 extend along the inclined surface on the end surface on the oblique side. Are formed at regular intervals. Further, between the adjacent light reflecting portions 55 of the light reflecting plates 54a to 54h, the angle formed by the perpendicular to the surface of the light reflecting plate 54 is about 45 degrees, and the light is reflected on the same plane parallel to the base. The parts 56 are formed at equal intervals. At this time, the distance between the light reflecting portion 56 and the bottom is gradually reduced in the order of the light reflecting plates 54a to 54d or the light reflecting plates 54e to 54h. The light reflecting portions 55 and 56 are formed by dichroic mirrors that reflect light in a specific wavelength band, and transmit the wavelength band of excitation light (details will be described later) for exciting the measurement object, and also the measurement object. It has the property of reflecting the wavelength band of measurement light emitted from.

  These light reflecting plates 54a to 54h are accommodated in the cutout portions 50 and 51 in a state where the bottom sides on the Y direction side are overlapped so that two sides other than the oblique sides are parallel to the Z axis and the Y axis. At this time, the eight light reflecting plates 54a to 54h are stacked in the order of the light reflecting plates 54a, 54h, 54b, 54g, 54c, 54f, 54d, and 54e so that the directions of the hypotenuses are alternated.

  Further, in each of the light reflecting plates 54a to 54h, a through hole 57 penetrating in the Y-axis direction is provided between the light reflecting portions 55 and 56 and the end face on the bottom side, and is reflected by the light reflecting portions 55 and 56. A plurality of holes 58 and 59 for passing the measured light toward the light incident plates 40 to 43 are provided.

  With the configuration of the light reflecting plate 54 described above, the light reflecting portions 55 and 56 are alternately directed to the different light incident plates 40 and 42 and the light incident plates 41 and 43 along the X-axis direction. The inclination angle of the reflection part 55 with respect to the Y axis and the Z axis is both about 45 degrees, and the inclination angle of the light reflection part 56 with respect to the Y axis and the X axis is both about 45 degrees. The light reflecting portions 55 are arranged so that the filter portions 44b and 45b are positioned on the extension lines in the Z-axis direction of the respective light reflecting portions 55. The light reflecting portions 56 are arranged on the X axis of each light reflecting portion 56. It arrange | positions so that the filter parts 46b and 47b may be located on the extended line in a direction.

  Returning to FIG. 6, a rectangular lens array 60 is fixed to the opening 49 of the reflector housing portion 48. The lens array 60 includes a lens member (light introducing portion) 60a for collecting the measurement light emitted from the measurement object A and guiding it in the + Y direction. The lens members 60a are arranged in a two-dimensional matrix with eight rows in the X-axis direction and eight rows in the Z-axis direction, and the light reflecting portions 55 and 56 are positioned on the extension lines in the condensing direction of the lens members 60a. To be done.

  Further, a rectangular cover part (incident surface) 61 having a channel frame provided at a position facing the lens member 60a is provided outside the lens array 60, and a slide glass or the like is provided outside the cover part 61. Then, the measuring object A is placed.

  A laser module (excitation light source) 62 for irradiating excitation light for exciting the measurement object A is provided at a position facing the lens array 60 with the reflector housing portion 48 interposed therebetween. A collimating lens 63 arranged in a matrix is fixed to the end surface of the laser module 62 on the reflecting plate housing portion 48 side. Each collimator lens 63 is disposed on an extension line in the Y-axis direction of the lens member 60a, and emits excitation light generated from the laser module 62 in the -Y direction as substantially parallel light. The excitation light emitted from the collimating lens 63 of the laser module 62 passes through the through hole 57 (see FIG. 7) of the light reflecting plate 54, and then passes through the light reflecting portions 55 and 56 and the lens member 60a to be measured. A is irradiated.

  The measurement light detection action of the light detection device 31 configured as described above will be described by taking two optical paths as an example. As shown in FIGS. 6 and 8A to 8B, the measurement light generated by the excitation of the measurement object A is guided in the Y direction by passing through the lens member 60a of the lens array 60. (Arrow L3). The measurement light is incident on the light reflecting portion 55 formed along the inclined surface S3 of the light reflecting plate 54b, and is reflected in the −Z direction by the light reflecting portion 55 toward the filter portion 45b of the bandpass filter 45. . Thereafter, the measurement light incident on the filter unit 45b is detected by the photodetection channel of the photomultiplier tube 33 facing the filter unit 45b.

  On the other hand, the measurement light transmitted through the lens member 60a adjacent in the −X direction is incident on the light reflecting portion 56 formed along the inclined surface S5 of the light reflecting plate 54g (arrow L4). Thereafter, the measurement light is reflected in the X direction toward the filter unit 46 b of the bandpass filter 46 by the light reflection unit 56. Thus, the measurement light incident on the filter unit 46b is detected by the photodetection channel of the photomultiplier tube 34 facing the filter unit 46b.

  Here, referring to FIG. 8A, the inclined surface S3 and the inclined surface S4 on which the light reflecting portion 55 is formed intersect on a straight line C2 having substantially the same distance from the light incident plates 40 and 41, that is, The light incident plates 40 and 41 intersect at a central position on a straight line. Similarly, referring to FIG. 8B, the inclined surface S5 and the inclined surface S6 where the light reflecting portion 56 is formed intersect on a straight line C3 having substantially the same distance from the light incident plates 42 and 43, that is, The light incident plates 42 and 43 intersect at a central position on a straight line. With the arrangement of the light incident portions 55 and 56, the optical path length from the cover portion 61 to the light incident plates 40, 41, 42, and 43 is made substantially the same for each light incident channel.

  According to the light detection device 31 described above, the measurement light generated from the measurement object A by the excitation light passes through the lens member 60a of the lens array 60 and is two-dimensionally arranged on the XZ plane. The guided measurement light is guided in the Y direction, and is reflected by the light reflecting portions 55 and 56, so that separate photomultiplier tubes 32, 33, 34 and 35 are alternately arranged in the X-axis direction and the Z-axis direction. To the light detection channel. At this time, the measurement light is incident in a direction perpendicular to the light incident plates 40 to 43 of the photomultiplier tubes 32 to 35. Therefore, even if the measurement light is increased in number of channels in order to increase the resolution during measurement, the distance between the light detection channels on which each measurement light is incident is increased, thereby reducing crosstalk between the light detection channels. Is done. As a result, measurement light can be simultaneously detected by a plurality of channels, so that measurement time can be shortened.

  In addition, the reflection plate housing 48 includes a light reflection portion 55 that reflects measurement light toward the light incident plate 41 and a light reflection portion 56 that reflects measurement light toward the light incidence plate 43 in the Z-axis direction. The light reflecting plates 54 a to 54 d formed alternately along the light incident plate 40, the light reflecting portion 55 that reflects the measuring light toward the light incident plate 40, and the light reflecting portion 56 that reflects the measuring light toward the light incident plate 42. And light reflecting plates 54e to 54h formed alternately along the Z-axis direction are accommodated. At this time, the light reflecting plates 54a, 54b, 54c, 54d and the light reflecting plates 54h, 54g, 54f, 54e are alternately stacked in the X-axis direction. As a result, it is easy to share a pair of light reflecting plates, and the manufacturing efficiency is improved, and the number of assembling steps is reduced.

  The light reflecting portion 55 has an inclination angle of about 45 degrees with respect to the Y axis and is formed along the inclination direction of the inclined surfaces S3 and S4 substantially parallel to the X axis. The light reflecting portion 56 is formed with respect to the Y axis. Since the inclination angle is about 45 degrees and it is formed along the inclination direction of the inclined surfaces S5 and S6 substantially parallel to the Z axis, each measurement light is different when measuring the two-dimensional distribution of the measurement light. It can lead to the light detection channel. In addition, since the optical path length from the incident surface to the light receiving surface is substantially the same in each photodetector, the uniformity of measurement sensitivity between the photodetection channels can be improved.

  In addition, the inclined surfaces S3 and S4 on which the light reflecting portion 55 is formed intersect on a straight line at the center position between the light incident plate 40 and the light incident plate 41, and the light reflecting portion 56 is formed. The inclined surfaces S5 and S6 intersect on a straight line at the center position between the light incident plate 42 and the light incident plate 43. Accordingly, since the optical path length from the incident surface to the light receiving surface is substantially the same among the four photodetectors, it is possible to further improve the uniformity of measurement sensitivity between the entire light detection channels.

  Further, since the laser module 62 is provided so as to face the lens member 60a of the lens array 60 with the reflector housing portion 48 interposed therebetween, the excitation light source is measured when measuring the distribution of light emitted from the measurement object. It is possible to prevent the optical path from being obstructed, and a complicated light guiding means for guiding the excitation light becomes unnecessary.

  In addition, this invention is not limited to embodiment mentioned above. For example, the light detection apparatus 1 may include an excitation light source. FIG. 9 is an exploded perspective view of a photodetection device 101 which is a modification of the present invention. The light detection apparatus 101 is provided with a laser module 162 in the vicinity of the bottom surface of the reflector housing portion 10, and a collimator lens 163 that makes excitation light substantially parallel light on the end surface on the reflector housing portion 10 side of the laser module 162. Is arranged. In addition, the lens array 160 and the cover part 161 are fixed to the opposite side of the laser module 162 across the reflector housing part 10, and the measurement object A is placed on the outer surface of the cover part 161. Referring to FIG. 10, the configuration of light reflecting plate 113 accommodated in reflecting plate accommodating portion 10 is the same as the configuration of light reflecting plate 13 (see FIG. 3) except that it has a through hole 157.

  Further, the light detection device 31 may not include an excitation light source. 11 and 12 are exploded perspective views of light detection devices 201 and 301 which are another modification of the present invention. The light detection device 201 has the same basic configuration as the light detection device 31 except that the excitation light source 62 is not provided. Further, the light detection device 301 is further provided with an optical fiber array F for allowing measurement light to enter the lens member 60 a instead of the cover portion 61. Referring to FIG. 13, the configuration of the light reflecting plate 254 accommodated in the reflecting plate accommodating portion 48 of the light detection devices 201 and 301 is the configuration of the reflecting plate 54 except that the through hole 57 is not provided (see FIG. 7). ).

  In the photodetector 1 of the first embodiment, the band-pass filters 8, 9, 16 are respectively provided on the outer sides of the light incident plates 6, 7 in the photomultiplier tubes 2, 3 and on the opening 15 of the reflecting plate housing 10. However, it is good also as providing a filter part in any one of the band pass filters 8, 9 or 16. When the bandpass filters 8 and 9 include the filter units 8b and 9b, the bandpass filter 16 can be omitted. When the bandpass filter 16 includes the bandpass filter 16, the filter unit of the bandpass filters 8 and 9 can be omitted. It is also possible to simply make it an opening.

  Furthermore, the photodetector used in the present invention is not limited to a multi-anode type photomultiplier tube as long as it constitutes a plurality of detection channels. For example, a light receiving element such as a charge coupled device (CCD) or an APD (Avalanche Photodiode) may be arranged corresponding to the position of each light detection channel.

  FIG. 14 shows a PET apparatus which is an application example of the present invention. In the PET device 401, eight light detection devices 301 are fixed radially in a state where the incident surface sides face each other on the same plane. The optical fiber array F of each photodetecting device 301 is accommodated in a rectangular parallelepiped-shaped optical fiber accommodating portion 402, and scintillators 403 having substantially the same shape as the inner side surface are provided on the inner end surfaces of these optical fiber accommodating portions 402. Is provided. In addition, a cable housing portion 404 that houses a cable extending from the photomultiplier tubes 32 to 35 is fixed to the outer end faces of the photomultiplier tubes 32 to 35 in these photodetectors 301. In such a PET apparatus 401, radiation emitted from the measurement object placed inside the scintillator 403 is converted into fluorescence and propagates through the optical fiber array F, and then the fluorescence of 2 is emitted by each light detection apparatus 301. A dimensional distribution is detected. As a result, three-dimensional measurement of radiation emitted from the measurement object is realized. With this configuration, it is possible to achieve a high spatial resolution and to suppress noise components in accidental simultaneous measurement as low as possible.

1 is a perspective view of a photodetecting device according to a first embodiment of the present invention. It is a disassembled perspective view of the photon detection apparatus of FIG. FIG. 3 is an exploded perspective view of the light reflecting plate of FIG. 2. It is a front view which shows the principal part of the photon detection apparatus of FIG. It is a perspective view of the photon detection apparatus which is 2nd Embodiment of this invention. It is a disassembled perspective view of the photon detection apparatus of FIG. FIG. 6 is an exploded perspective view of the light reflecting plate in FIG. 5. (A) is a front view which shows the principal part of the photodetector in FIG. 5, (b) is a side view which shows the principal part of the photodetector in FIG. It is a disassembled perspective view of the photon detection apparatus which is a modification of this invention. FIG. 10 is an exploded perspective view of the light reflecting plate of FIG. 9. It is a disassembled perspective view of the photodetector which is another modification of this invention. It is a disassembled perspective view of the photodetector which is another modification of this invention. FIG. 13 is an exploded perspective view of the light reflecting plate of FIGS. 11 and 12. It is a perspective view of a PET apparatus which is an application example of the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1,31,101,201,301 ... Photodetector, 2, 3, 32-35 ... Photomultiplier tube (photodetector), 6, 7, 40-43 ... Light incident plate (light-receiving surface), 13, 54a to 54h, 113, 254 ... light reflecting plate (light reflecting member), 14, 55, 56 ... light reflecting portion, 16 ... band pass filter, 17 ... spectral plate, 19 ... dichroic mirror array (light introducing portion), 60 , 160... Lens array (light introducing portion), 61, 161. Cover portion (incident surface), 62, 162... Laser module (excitation light source), S1 to S6.

Claims (10)

A light detection device for detecting a distribution of measurement light incident on an incident surface,
A first photodetector having a first light receiving surface in which a plurality of photodetector channels are arranged in at least a first direction;
A plurality of light detection channels arranged in at least the first direction and having a second light receiving surface facing substantially parallel to the first light receiving surface;
A plurality of light introduction sections arranged in at least the first direction on the incident surface and introducing the measurement light in a second direction substantially perpendicular to the first direction;
The separate light detections corresponding to the measurement light, which are arranged between the first light receiving surface and the second light receiving surface, on an extension line in the second direction of the plurality of light introducing portions. With a plurality of light reflecting parts that reflect toward the channel,
The first and second photodetectors are two-dimensionally along the first and second light receiving surfaces in a direction substantially perpendicular to the first direction and the first direction, respectively. Having a plurality of photodetection channels arranged;
The plurality of light introducing portions are two-dimensionally arranged along the incident surface in the first direction and a third direction substantially perpendicular to the first direction,
The plurality of light reflecting portions are formed to alternately face the first light receiving surface side and the second light receiving surface side along the first direction.
An optical detection device characterized by that. The plurality of light introducing portions introduce the measurement light in the second direction substantially perpendicular to the third direction,
The plurality of light reflecting portions have an inclination angle with respect to the second direction of approximately 45 degrees and are formed along an inclination direction of an inclined surface substantially parallel to the first direction.
The photodetection device according to claim 1 . The inclined surface on which the plurality of light reflecting portions are formed intersects in a straight line at a center position between the first light receiving surface and the second light receiving surface in the third direction.
The photodetection device according to claim 2 . It said first and second photodetectors, the multi-anode type optical detection device according to any one of claims 1 to 3, characterized in that a photomultiplier tube. A light detection device for detecting a distribution of measurement light incident on an incident surface,
A first photodetector having a plurality of first light receiving surface of the light detection channels are two-dimensionally arranged in a substantially perpendicular second direction to the first direction and the first direction,
A plurality of light detection channels are two-dimensionally arranged in the first direction and the second direction, and have a second light receiving surface facing substantially parallel to the first light receiving surface. A detector;
A third light detection in which a plurality of light detection channels have a third direction that is a perpendicular direction of the first and second light receiving surfaces and a third light receiving surface that is two-dimensionally arranged in the second direction. And
A plurality of light detection channels are two-dimensionally arranged in the third direction and the second direction, and a fourth light having a fourth light receiving surface facing substantially parallel to the third light receiving surface. A detector;
A plurality of light introducing portions that are two-dimensionally arranged in the first direction and the third direction on the incident surface and introduce the measurement light in the second direction;
In the region surrounded by the first to fourth light receiving surfaces, the plurality of light introducing portions are arranged on extension lines in the second direction, and the measurement light is directed to the corresponding separate light detection channels. A plurality of light reflecting parts to be reflected,
The plurality of light reflecting portions are formed to alternately face different directions along the first and third directions.
An optical detection device characterized by that. The plurality of light reflecting portions are:
Alternately along the third direction, a light reflecting surface that reflects the measurement light toward the second light receiving surface, and a light reflecting surface that reflects the measurement light toward the fourth light receiving surface A first light reflecting member formed with
Alternately along the third direction, a light reflecting surface that reflects the measuring light toward the first light receiving surface, and a light reflecting surface that reflects the measuring light toward the third light receiving surface. A second light reflecting member formed with
The first light reflecting member and the second light reflecting member are alternately arranged in the first direction.
The photodetection device according to claim 5 . The plurality of light reflecting portions have an inclination angle of about 45 degrees with respect to the second direction, and are formed along an inclination direction of an inclined surface substantially parallel to the first direction. An inclination angle with respect to the direction of 2 is approximately 45 degrees, and is formed along an inclination direction of an inclined surface substantially parallel to the third direction.
The photodetection device according to claim 5 or 6 . The inclined surface on which the plurality of light reflecting portions are formed intersects on a straight line at a center position between the first light receiving surface and the second light receiving surface in the third direction, and Intersecting in a straight line at a central position between the third light receiving surface and the fourth light receiving surface in the first direction;
The photodetection device according to claim 7 . The first to fourth optical detectors, optical detection device according to any one of claims 5-8, characterized in that the photomultiplier tube of the multi-anode type. An excitation light source that is provided opposite to the plurality of light introduction portions across the plurality of light reflection portions, and that emits excitation light for exciting the measurement object in the second direction;
The plurality of light reflecting portions have a dichroic mirror that transmits light in the wavelength band of the excitation light and reflects light in the wavelength band of measurement light emitted from the measurement object.
Light detecting device according to any of claims 1-9, characterized in that.

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