JP3908681B2 - Weak light two-dimensional position detection system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a weak light two-dimensional position detection system that detects weak electromagnetic waves and particles emitted two-dimensionally.
[0002]
[Prior art]
Conventionally, a weak light two-dimensional position detection system that can be used for a space telescope for detecting which cell of a DNA chip has formed a hybrid with DNA in a specimen or observing cosmic rays has been proposed. Yes.
[0003]
FIG. 8 is a schematic block diagram of a conventional weak light two-dimensional position detection system. In FIG. 8, a conventional weak light two-dimensional position detection system 100 obtains a detection unit 102 that takes in weak light and converts an electric signal, and a position of weak light based on an output signal of the detection unit 102. And a signal processing unit 104 (see, for example, Patent Document 1).
[0004]
The detection unit 102 includes a detection unit 102a having a plurality of microcapillaries for detecting and amplifying weak light, and an operation control unit 102b for operating the detection unit 102a.
[0005]
The signal processing unit 104 includes a preprocessing circuit 104a that reads and preprocesses the output signal of the detection unit 102, a data collection circuit 104b that is connected to the output side of the preprocessing circuit 104a and collects data, and the data collection circuit The data analysis circuit 104c is configured to take in the data from 104b and the control signal from the operation control unit 102b and analyze the position of weak light based on these signals. An output device 106 such as a display device or a printer, an external storage device 108, and the like are connected to the output side of the data analysis circuit 104c.
[0006]
The detection unit 102a of the detection unit 102 is provided with a light shielding container that shields extraneous light, and a lens is attached to the front end surface of the light shielding container. Further, in the light shielding container, an optical filter and a two-dimensional light receiver are disposed in this order behind the lens. This optical filter cuts off an unnecessary frequency band of weak light and selectively transmits light in a frequency band corresponding to fluorescence to enter the two-dimensional light receiver.
[0007]
FIG. 9 is a partial cross-sectional view of the two-dimensional light receiver in the conventional weak light two-dimensional position detection system. In FIG. 9, the two-dimensional light receiver 110 has a vacuum vessel 112, and a photoelectric conversion unit 114 formed by vapor deposition or the like is provided on the front surface of the vacuum vessel 112. In the two-dimensional light receiver 110, a microchannel plate 116 and a detection module 118 are arranged in this order in the vacuum vessel 112 next to the photoelectric conversion unit 114. In the two-dimensional light receiver 110, the photoelectric conversion unit 114, the microchannel plate 116, and the detection module 118 are arranged close to each other.
[0008]
The photoelectric conversion unit 114 emits electrons upon incidence of photons. The microchannel plate 116 amplifies the electrons emitted from the photoelectric conversion unit 114, and a plurality of electron amplification units arranged in a matrix so as to face the photoelectric conversion unit 114 are provided. Further, the detection module 118 is provided corresponding to each of the electronic amplifying parts constituting the microchannel plate 116, and includes detection electrodes 122, 122,... And a switching integrated circuit 120.
[0009]
In such a weak light two-dimensional position detection system 100, when weak light is incident on the two-dimensional light receiver 110 constituting the detection unit 102a of the detection unit 102, the photoelectric conversion unit 114 converts the weak light into electrons (photoelectrons). Converted. The electrons are amplified in the microchannel plate 116 and enter the detection electrode 122 of the detection module 118. The detection module 118 outputs a current corresponding to the amount of electrons incident on the detection electrode 122. This current signal is input to the preprocessing circuit 104 a of the signal processing unit 104 as an output signal of the detection unit 102. The preprocessing circuit 104a converts the current signal into a voltage signal and further amplifies it. The output signal of the preprocessing circuit 104a is supplied to the data collection circuit 104b, and the data collection circuit 104b collects data. The data from the data collection circuit 104b and the control signal from the operation control unit 102b are input to the data analysis circuit 104c. The data analysis circuit 104c analyzes the position of weak light based on the two pieces of captured data.
[0010]
The two-dimensional light receiver 110 in such a weak light two-dimensional position detection system has a microchannel plate 116 and a detection module 118 assembled in a vacuum vessel 112, and the vacuum vessel 112 is disposed in a vacuum atmosphere. Is made by vacuuming and sealing in vacuum. In the above-described conventional two-dimensional light receiver 110, in order to increase the degree of vacuum inside the vacuum vessel 112, it is necessary to strip off gas molecules adhering to the wall surface of the vacuum vessel 112 and the element surface. In the stage of vacuum-sealing 112, it is common practice to heat the entire vacuum vessel 112 at, for example, several hundred [° C.].
[0011]
[Patent Document 1]
JP 2003-004636 A
[Problems to be solved by the invention]
However, in the conventional two-dimensional light receiver 110 described above, the switching integrated circuit 120 of the detection module 118 is arranged inside the vacuum vessel 112. For this reason, if the vacuum vessel 112 is heated to a high temperature for vacuum sealing, the integrated circuit 120 will be damaged by the heat, so that the heating cannot be sufficiently performed to protect the switching integrated circuit 120. It was. For this reason, there is a problem that the degree of vacuum does not increase and the photocathode is deteriorated or becomes an obstacle at the time of electron multiplication. For this reason, the manufacturing method which can be heated at high temperature was requested | required.
[0013]
The present invention has been made in order to eliminate the above-mentioned conventional drawbacks, and an object of the present invention is to enable high-temperature heating and to make the inside of a vacuum vessel have a high degree of vacuum.
[0014]
[Means for Solving the Problems]
In order to achieve the above object, a weak light two-dimensional position detection system according to the present invention amplifies electrons emitted from a photoelectric conversion unit that is arranged facing the photoelectric conversion unit and emits electrons upon incidence of light. A plurality of electron amplifying units that are provided in a matrix form, corresponding to the row or column of each of the electron amplifying units constituting the microchannel plate, and electrons from the electron amplifying unit Provided with two detectors each including an electron detector having an incident band-shaped electron collecting electrode or an electron collecting electrode in which a plurality of electrode pieces are linearly connected in series, and can be driven independently a light distribution means comprising a mirror element, a preprocessing circuit for the output signal from the two detecting portions pretreated respectively, collect the output signals from the respective preprocessing circuits, their And a signal processing unit for determining the position of the light incident on the light distribution means based on an output signal, and the detection units are arranged in different directions around the light distribution means, and The arrangement direction of the band-shaped electron collecting electrode or the electron collecting electrode in which the electrode pieces are connected in series in the detection unit is crossed, and the light distribution unit is configured so that the mirror elements adjacent to each other are alternately inclined in different directions. The incident light is reflected alternately toward the two detection units .
[0015]
The weak light is supplied to the two detection units by the light distribution means. Multiple each detector, along with being located in different directions around the optical allocation unit, the plurality of electron collecting electrode strip constituting the electron detector or a plurality of electrode pieces, and linearly connected in series Since the electron collecting electrodes are arranged so as to intersect, for example, orthogonally (in the X axis and the Y axis), detection signals for the X coordinate position and the Y coordinate position are obtained. The detection signal from the light receiving unit on the X axis side is preprocessed as X axis data by the X axis preprocessing circuit. The detection signal from the light receiving unit on the Y axis side is preprocessed as Y axis data by the Y axis preprocessing circuit. The preprocessed X-axis output signal and Y-axis output signal from each preprocessing circuit are supplied to the signal processing unit. The signal processing unit analyzes the position of the weak light incident on the light distribution means based on the X-axis output signal and the Y-axis output signal data.
[0016]
This eliminates the need to provide a switching integrated circuit or the like in the light receiving unit. Therefore, the vacuum container of the light receiving unit can be heat-treated at a high temperature, the inside of the vacuum container can be made to have a high degree of vacuum, and detection accuracy can be improved. Since each light receiving unit outputs an X coordinate signal and a Y coordinate signal, a complicated switching circuit and readout circuit are not required, and the control can be simplified. The light distribution means can be constituted by a mirror or a beam splitter whose tilt direction can be switched.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of a weak light two-dimensional position detection system according to the present invention will be described in detail with reference to the accompanying drawings.
[0018]
1 to 6 are diagrams for explaining a first embodiment of a weak light two-dimensional position detection system according to the present invention.
FIG. 1 is a schematic configuration diagram showing a first embodiment of the weak light two-dimensional position detection system according to the present invention.
[0019]
In FIG. 1, the weak light two-dimensional position detection system according to the present invention is roughly composed of detection units 2X and 2Y, a signal processing unit 4, a light distribution unit 6, and preprocessing circuits 8X and 8Y.
Although described in detail later, the detection unit 2X is a detector that detects weak light, converts it into an electrical signal, and outputs an X coordinate signal. Although the details will be described later, the detection unit 2Y is a detector that detects weak light, converts it into an electrical signal, and outputs a Y coordinate signal. The light distribution unit 6 is a unit that maintains a predetermined positional relationship with respect to the detection units 2X and 2Y and distributes weak light (incident light) incident on the two detection units 2X and 2Y. The preprocessing circuits 8X and 8Y are circuits for preprocessing output signals from the two detection units 2X and 2Y, respectively.
[0020]
The signal processing unit 4 collects output signals from the pre-processing circuits 8X and 8Y, and based on the collected output signals, the light (incident to the photoelectric conversion units of the two detection units 2X and 2Y, respectively) This is a unit for determining the position of photons.
The light distribution means 6 is composed of a mirror that can move at high speed, and reflects weak light equally to the two detectors 2X and 2Y.
[0021]
The signal processing unit 4 also includes a data collection circuit 4a that collects detection signals from the preprocessing circuits 8X and 8Y, and collected data (X-axis detection signal and Y-axis detection signal) from the data collection circuit 4a. Based on this, the positions of the photons incident on the photoelectric conversion units of the two detection units 2X and 2Y are calculated.
[0022]
FIG. 2 is a schematic configuration diagram showing a detection unit in the first embodiment of the feeble light two-dimensional position detection system according to the present invention.
Since the detection unit 2X and the detection unit 2Y are formed in exactly the same structure, the structure of the detection unit 2X will be described, and the description of the structure of the detection unit 2Y will be omitted. The detection unit 2X is roughly divided into a light receiver 10, a light shielding container 20, a lens 22, and an optical filter 24. The light shielding container 20 is a container that shields extraneous light, and a lens 22 is attached to the front end surface of the light shielding container 20. Furthermore, an optical filter 24 and a light receiver 10 are arranged in the light shielding container 20 behind the lens 22 in this order. The optical filter 24 cuts off an unnecessary frequency band of weak light and selectively transmits light in a frequency band corresponding to fluorescence to enter the light receiver 10.
[0023]
FIG. 3 is a schematic configuration diagram showing the light receiver of the detection unit in the first embodiment of the feeble light two-dimensional position detection system according to the present invention. FIG. 4 is a schematic configuration diagram showing the electron detector of the light receiver of the detection unit in the first embodiment of the weak light two-dimensional position detection system according to the present invention.
[0024]
In FIG. 3, the light receiver 10 has a vacuum container 12, and a photoelectric conversion unit 14 is provided on the front surface of the vacuum container 12. In the light receiver 10, a microchannel plate 16 and an electron detector 18 are arranged in this order in the vacuum vessel 12 next to the photoelectric conversion unit 14.
[0025]
More specifically, the photoelectric conversion unit 14 is formed as a thin film by vapor deposition or the like, and emits electrons upon incidence of photons. Further, the microchannel plate 16 is arranged facing the photoelectric conversion unit 14, and a plurality of electron amplification units that amplify the electrons emitted by the photoelectric conversion unit 14 are arranged in a matrix. Each electron amplifying unit is constituted by a photomultiplier tube called a microcapillary.
[0026]
As shown in FIG. 4, the electron detector 18 has a plurality of electron collecting electrodes 18b, 18b,... Provided on the surface of the ceramic material plate 18a. These electron collecting electrodes 18b, 18b,... Are formed by linearly and electrically connecting electrode pieces 18d, 18d,. In the case of the embodiment, n × n electrode pieces 18d, 18d,... Are provided corresponding to the microcapillaries (electron amplification units) constituting the microchannel plate 16. A plurality of electron collecting electrodes 18b, 18b,... Are provided corresponding to the rows or columns of the respective electron amplifiers of the microchannel plate 16, and as shown in FIG. 4, connection terminals 18c, 18c,. It is connected to the. These connection terminals 18c, 18c,... Are electrically connected to corresponding external terminals (not shown) provided outside the vacuum vessel 12. The electrode pieces 18d do not have to correspond one-to-one with the microcapillaries, and can be formed in an appropriate size.
[0027]
FIG. 5 is a schematic explanatory view showing an arrangement state of the electron detectors provided in the light receiver constituting the detection unit in the first embodiment of the weak light two-dimensional position detection system according to the present invention. In FIG. 5, only the arrangement of the electron detectors 18X and 18Y incorporated in the light receivers 10X and 10Y is displayed, not the arrangement of the detectors 2X and 2Y.
[0028]
In FIG. 5, the electron detectors 18X and 18Y of the detectors 2X and 2Y are arranged in two directions with a predetermined angle around the light distribution means 6, as shown in FIG. In addition, the electron detectors 18X and 18Y are arranged such that the series connection direction (arrangement direction) of the electron collecting electrodes 18bX, 18bX,..., And the electron collecting electrodes 18bY, 18bY,. It is arranged in. In the embodiment, the electron collecting electrodes 18bX and 18bY are arranged so that the arrangement directions thereof are orthogonal to each other (in the X axis and the Y axis). As shown in FIG. 5, the weak incident light is incident on a light distribution means 6 composed of a mirror that can move at high speed via a lens system (not shown).
[0029]
In the case of the embodiment, the light distribution means 6 is constituted by a micromirror array composed of minute mirror elements. The mirror elements are arranged in a matrix and are driven in synchronization with each other. The light distribution means 6 is inclined by a predetermined angle alternately in the clockwise direction and the counterclockwise direction in FIG. 5 as shown by the solid line and the broken line in FIG. Light is reflected in a predetermined direction. The reflected light reflected by the light distribution means 6 enters the photoelectric conversion units 14X and 14Y of the detection units 2X and 2Y. Electrons from the photoelectric conversion units 14X and 14Y are optically amplified by the microchannel plates 16X and 16Y of the detection units 2X and 2Y, and electrodes of the electron collection electrodes 18bX, 18bX, ..., the electron collection electrodes 18bY, 18bY, ... It is supplied to the piece 18d. The light distribution means 6 may be constituted by a normal mirror.
[0030]
The operation of such a weak light two-dimensional position detection system will be described.
As shown in FIG. 5, the weak incident light is incident on the light distribution means 6 composed of a mirror that can move at high speed. The light distribution means 6 reflects the incident light while alternately tilting in the clockwise direction and the counterclockwise direction of FIG. 5 at intervals of about nanoseconds. Alternatively, for example, mirror elements adjacent to each other are alternately reflected in different directions (clockwise and counterclockwise in FIG. 5), that is, alternately in different directions in a checkered pattern. The reflected light from the light distribution unit 6 is incident on the photoelectric conversion units 14X and 14Y of the detection units 2X and 2Y. Electrons from the photoelectric conversion units 14X and 14Y are amplified by the microchannel plates 16X and 16Y of the detection units 2X and 2Y to form electron collection electrodes 18bX, 18bX,..., Electron collection electrodes 18bY, 18bY,. To the electrode piece 18d.
[0031]
The electron collecting electrodes 18bX, 18bX,... Of the detection unit 2X input an output signal (current signal) indicating the position of the X coordinate to the preprocessing circuit 8X when electrons enter the electrode piece 18d. Similarly, in the detection unit 2Y, the position signal of the Y coordinate is input to the preprocessing circuit 8Y from the electron collection electrodes 18bY, 18bY,.
[0032]
Here, the electron detectors 18X and 18Y are arranged such that the electron collecting electrodes 18bX, 18bX,..., And the electron collecting electrodes 18bY, 18bY,. As a result, detection signals in the X-axis direction and the Y-axis direction are obtained. The detection signal from the X-axis light receiver 10X is preprocessed by the X-axis preprocessing circuit 8X as X-axis data. A detection signal from the Y-axis light receiver 10Y is preprocessed as Y-axis data by the Y-axis preprocessing circuit 8Y. Since the detection signals are currents, the preprocessing circuits 8X and 8Y convert them into voltage signals and amplify them to a certain level.
[0033]
The preprocessed X-axis output signal and Y-axis output signal from the preprocessing circuits 8X and 8Y are supplied to the signal processing unit 4. In the signal processing unit 4, the X-axis output signal and the Y-axis output signal data are collected by the data collection circuit 4a. The X-axis output signal and the Y-axis output signal from the data collection circuit 4a are input to the data analysis circuit 4b. The data analysis circuit 4b obtains the position of each electrode piece 18d on which electrons are incident from the microchannel plate 16 based on the output signals of the electron detectors 8X and 8Y. Further, the data analysis circuit 4b calculates the position of the mirror element of the micromirror array that reflects the incident light from the determined position of each electrode piece 18d based on a predetermined formula. Thereby, the position of the weak light incident on the light distribution means 6 can be obtained.
[0034]
According to the light receiver 10 in the weak light two-dimensional position detection system according to the present invention, since the integrated circuit is not provided in the vacuum container 12, the entire vacuum container 12 is heated at a high temperature and evacuated in the manufacturing process. The inside of the vacuum vessel 12 can be kept at a high degree of vacuum.
[0035]
FIG. 6 is a plan view showing the structure of the electron detector of the light receiver constituting the detection unit according to the second embodiment of the present invention. In FIG. 6, the light receiver 10 ′ of the detection unit in the second embodiment of the present invention includes an electron detector 18 ′ having a structure different from that of the first embodiment. Here, as shown in FIG. 6, the electron detector 18 ′ has electron collecting electrodes 18 b ′, 18 b ′,... Formed on the surface of the ceramic material plate 18 a by a thin metal film in a linear strip shape. These electron collecting electrodes 18b ′, 18b ′,... Are provided in n columns corresponding to the rows or columns of the respective electron amplifying parts constituting the microchannel plate 16. Further, each of the electron collecting electrodes 18b ′, 18b ′,... Is connected to the connection terminals 18c, 18c,. Even with the electron detector 18 ′ of the light receiver 10 ′ having such a structure, an X coordinate signal and a Y coordinate signal are output when light is incident, and the position of the incident plate light can be detected by the light distribution means 6. . In the second embodiment, the electron collecting electrodes 18b ′, 18b ′,...
[0036]
FIG. 7 is a layout diagram showing the relationship between the light distribution means and the detectors 2X and 2Y in the third embodiment of the feeble light two-dimensional position detection system according to the present invention.
In FIG. 7, the detectors 2X and 2Y are arranged at right angles around the light distribution means 6 ′. As shown in FIG. 6, the electron detectors of the detectors 2X and 2Y are arranged such that the electron collecting electrodes arranged in a straight line are orthogonal to each other (in the X axis and the Y axis). The light distribution means 6 ′ is composed of a beam splitter such as a half mirror.
[0037]
As shown in FIG. 7, the light distribution means 6 ′ constituted by the beam splitter reflects a part of the weak incident light and transmits the other part. The reflected light from the light distribution means 6 ′ is incident on the photoelectric conversion unit of the detection unit 2X, and the transmitted light is incident on the photoelectric conversion unit of the detection unit 2Y. Electrons from the photoelectric conversion unit are optically amplified by the microchannel plates of the detection units 2X and 2Y and supplied to the electron collecting electrode.
[0038]
According to the third embodiment, since there is no movable part, there is an advantage that the weak light can be stably divided into equal parts. In addition, all of the incident light can be received, and detection efficiency can be improved and detection accuracy can be improved.
[0039]
Conventionally, a detection module of a two-dimensional light receiver requires n × n pixels (electron collecting electrodes) and n × n output terminals to detect the position of the light source. However, according to the present invention, since it is sufficient to configure 2n output terminals, the post-processing circuit can be greatly simplified, and the incident light position can be obtained quickly.
[0040]
【The invention's effect】
As described above, according to the present invention, two detection units including an electron detector provided with an electron collection electrode such as a belt-like shape are provided, the arrangement directions of the respective electron collection electrodes are crossed, and the light distribution means Since the weak light is applied to the two detection units, the vacuum vessel can be heated to a high temperature to be evacuated, and the inside of the vacuum vessel can be kept at a high degree of vacuum.
[0041]
In addition, according to the present invention, the output of the electron detectors constituting the detector can be reduced to 2n, so that the post-processing circuit can be greatly simplified and the incident light position can be quickly obtained. it can.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing a first embodiment of a weak light two-dimensional position detection system according to the present invention.
FIG. 2 is a schematic configuration diagram showing a detection unit in the first embodiment of the weak light two-dimensional position detection system according to the present invention.
FIG. 3 is a schematic configuration diagram showing a light receiver of a detection unit in the first embodiment of the weak light two-dimensional position detection system according to the present invention.
FIG. 4 is a schematic configuration diagram showing an electron detector of a light receiver of a detection unit in the first embodiment of the weak light two-dimensional position detection system according to the present invention.
FIG. 5 is a schematic explanatory diagram for explaining an arrangement state of electron detectors of a light receiver of a detection unit in the first embodiment of the weak light two-dimensional position detection system according to the present invention.
FIG. 6 is a plan view showing the structure of the electron detector of the light receiver of the detection unit in the second embodiment of the weak light two-dimensional position detection system according to the present invention.
FIG. 7 is a layout diagram showing the relationship between light distribution means and detectors 2X and 2Y in the third embodiment of the weak light two-dimensional position detection system according to the present invention.
FIG. 8 is a schematic block diagram of a conventional weak light two-dimensional position detection system.
FIG. 9 is a partial cross-sectional view of a two-dimensional light receiver in the conventional weak light two-dimensional position detection system.
[Explanation of symbols]
2X, 2Y ......... detection unit, 4 ......... signal processing unit, 6, 6 '......... light distribution means (mirror, beam splitter), 8X, 8Y ......... preprocessing circuit, 10, 10' ... …… Photoreceptor, 12 ………… Vacuum container, 14 …… Photoelectric conversion unit, 16 ………… Microchannel plate, 18 ………… Electron detector, 18 a …… Ceramic material plate, 18 b, 18 b ′ …… ... Electron collecting electrode, 18d ... ... Electrode piece.

Claims (2)

A photoelectric conversion unit that emits electrons upon incidence of light, a microchannel plate in which a plurality of electron amplification units that are arranged facing the photoelectric conversion unit and amplify electrons emitted from the photoelectric conversion unit are provided in a matrix, the microchannel A strip-shaped electron collecting electrode or a plurality of electrode pieces linearly connected in series is provided corresponding to the row or column of each of the electron amplifying units constituting the plate. Two detectors equipped with a light receiver made of an electron detector having an electron collecting electrode are provided,
A light distribution means comprising a plurality of mirror elements that can be driven independently ;
A preprocessing circuit for preprocessing output signals from the two detection units, respectively;
A signal processing unit that collects output signals from each of the preprocessing circuits and obtains the position of the light incident on the light distribution means based on the output signals; and
The detection units are arranged in different directions with the light distribution means as a center, and the arrangement directions of the band-like electron collection electrodes or the electron collection electrodes in which the electrode pieces of the detection units are connected in series are crossed. Yes Te,
The light distribution means is configured such that the mirror elements adjacent to each other are alternately inclined in different directions, and the incident light is alternately reflected toward the two detection units.
A weak light two-dimensional position detection system. A plurality of the electron collection electrodes of the two detection units are provided,
The electron collecting electrode of one of the detection units and the electron collecting electrode of the other detection unit are orthogonal to each other,
The weak light two-dimensional position detection system according to claim 1.

Images