JPS6358749A - Transmission electron microscope - Google Patents

Abstract

PURPOSE:To record an image on a sensor continuously at a high speed by providing a holding position where recorded sensors are held between the recording position of the information to the two-dimensional sensor and the reading position of the information recorded on the sensor. CONSTITUTION:A position A in a vacuum chamber 3B is the recording position of the image projected by a projecting lens 36, and a cassette 39 inserted with a cummulative phosphor sheet is arranged at this position A. A position C is the reading position of the information recorded on the said sheet, the laser light from a laser generator 43 is reflected by a reflecting mirror 44 and illuminated through a light penetrating window 45 to the sheet in the cassette 39 arranged at this position. A holding container 42 of cassettes 39 is arranged at the position B, and if a gear 41 is rotated at the position A and the cassette 39 is transferred in the arrow direction, this cassette 39 is dropped in a holding container 42. By providing the position B between the position A and the position C above, the image to the sensor can be recorded continuously at high speed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an electron microscope, and more particularly to a transmission electron microscope capable of continuously recording high-quality images with insect sensitivity at a high speed.

[Prior art 1] Generally, in a transmission electron microscope, a sample is irradiated with a focused electron beam, and the electron beam transmitted through the sample forms a diffraction pattern of the sample on the back focal plane of an objective lens. By causing interference again, an enlarged image of the sample is formed. If this enlarged Q is projected onto a fluorescent screen using a projection lens, an enlarged transmitted image of the sample can be observed, and the (p
By projecting the focal plane, an enlarged diffraction pattern of sample rl can be observed. In order to observe the enlarged transmission image or diffraction pattern (hereinafter referred to as a transmission electron beam image) formed in this way, conventionally, a photographic film is placed on the imaging plane of a projection lens and the transmission electron beam image is exposed. Alternatively, an image intensifier was arranged to convey a transmitted electron beam image.

However, photographic film has the drawbacks of low sensitivity to electron beams and cumbersome development processing.Also, when using an image intensifier, the sharpness of the image is low and the image is distorted. There is a problem in that it is easy to occur.

By the way, recently, the FJ4 electron beam energy has been accumulated.
Extremely sensitive recording media have been proposed that can emit the accumulated electron beam energy as light when irradiated with light or heated. FIG. 3 is a cross-sectional view of a stimulable phosphor sheet that is excited by light irradiation and is suitable for use as such a recording medium, in which 1 is a stimulable phosphor sheet, 2 is a support, and 3 is a stimulable phosphor sheet. is a stimulable phosphor layered on a support 2. In the figure, the support 2 includes a polyethylene sheet with a thickness of about 100 to 200 mm, a plastic film, an aluminum plate with a thickness of 0.5 to 1 mm,
A ~3mn+ glass plate is used, and it can be either transparent or opaque. If it is opaque, light emission is detected from the side to which the excitation light is applied, but if it is transparent, it is detected from the side to which the excitation light is applied or vice versa. Luminescence can be detected from either side or from both sides.

As such a stimulable phosphor, for example, JP-A-55
(Bat-χ-Fang, MQz, Cay) FX: aEu (where X is at least one of C2 and Br,
X and y are 0<x+y≦0.6 xy≠0, and a is 10-'≦a≦5X10'. ), BaFX-xNaX'″: aEu2+ (however,
X and X- are each at least one of C2, 3r, and I, and X and a are Ox≦20<a≦0.2). Can be done.

Then, such a stimulable phosphor is dispersed in a suitable binder and coated on the support 2 to a thickness of approximately 50 to +000 mm. Note that when the stimulable phosphor layer is a self-supporting body, it can become a stimulable phosphor sheet by itself.

When the stimulable phosphor sheet formed in this way is irradiated with radiation such as an electron beam, part of the energy of the radiation is accumulated in the phosphor, and then the phosphor is irradiated with excitation light such as visible light. Then, the phosphor emits fluorescence (stimulated luminescence) in response to the accumulated energy. Furthermore, instead of the stimulable phosphor being excited by the aforementioned light irradiation, the emission T; ij I! is accumulated by heating. A thermophosphor that emits il energy as thermofluorescence may also be used. In this case, for example, Na2804, Mn5Oa, Sr
M in the purchased M compounds of SO4, CaSO4, BaSO4'8
It is sufficient to use a compound containing at least one trace amount of additives such as n, Dy, Tm, etc., and the method for manufacturing the thermophosphor sheet is as follows:
This is similar to the stimulable phosphor sheet described above.

Therefore, a recording medium such as a stimulable phosphor sheet or a thermophosphor sheet is placed on the imaging surface of an electron microscope to accumulate and record transmitted electron beam images, and the recording medium is scanned with excitation light such as visible light. If the material is heated and heated to generate fluorescence, and this fluorescence is read photoelectrically, an electrical signal corresponding to the transmitted electron beam image will be obtained. If the electrical image signal obtained in this way is used, an electron microscope VT@ can be displayed on a display such as a cathode ray tube, or it can be permanently recorded as a hard copy.
It is also possible to store the information on a hard drive disk or the like.

Problems to be Solved by the Invention] For example, Japanese Patent Laid-Open No. 121249/1983 discloses a transmission electron microscope using a stimulable phosphor sheet as shown in FIG. In the figure, reference numeral 11 denotes a vacuum chamber at the bottom of the mirror body, and inside the vacuum chamber 11, an endless belt 14 stretched around rollers 12 and 13 is disposed. Four stimulable phosphor sheets 15 are placed on the belt 14.

Reference numeral 16 denotes an electron beam, and the electron beam is irradiated onto the sheet 15 placed at the position (A), so that a transmitted electron beam image is accumulated and recorded on the sheet. The sheet on which the image is recorded advances in the direction of the arrow in the figure as the belt 14 moves due to the rotation of the rollers 12 and 13, and the recorded information is read at the position (B). That is, at the position (B), the laser beam from the laser oscillator 16 is reflected by the reflecting mirror 17.
The light is reflected by the sheet 15 and transmitted through the light transmission window 18.
is irradiated. The laser beam is scanned by a reflecting mirror 17 in a direction perpendicular to the plane of the paper in the figure, and as the belt 49 moves, the sheet is two-dimensionally scanned by the laser beam. Fluorescence generated from the sheet upon irradiation with the laser beam is detected by a photodetector 19.

A signal detected by one of the photodetectors is supplied to a cathode ray tube or the like through a signal processing circuit (not shown), and is also recorded on a magnetic tape or the like. The sheet whose information has been read at the position (B) moves with the movement of the belt 14, and the information recorded on the sheet is erased at the position (C).

That is, at position (C), light from the light source 20 is irradiated onto the sheet through the light transmission window 21, and the sheet is reproduced by erasing information. The sheet reproduced at position (C) is moved to position <A> by movement of the belt, and a transmission electron beam image is recorded again.

Now, with the configuration described above, the time required to record an image at position (A>) is less than 0.1 seconds, whereas it takes about a minute and a half to read the information at position (B). , (C) It takes about 30 seconds to erase the information at the position. Therefore, the speed of movement of the belt 14 is limited by the reading of the information that takes the longest time, and the recording of the image is limited. Although the time is short, it is impossible to record a large number of electron beam images continuously at high speed.

The present invention has been made in view of the above-mentioned points, and provides a transmission electron microscope using a two-dimensional sensor such as a MIFI phosphor sheet that can continuously record electron beam images at high speed. It is an object.

[Means for Solving the Problems] A transmission electron microscope based on the present invention includes means for enlarging and projecting a sample image, a two-dimensional sensor for accumulating and recording the projected sample image, and a means for projecting a sample image onto the two-dimensional sensor. means for conveying the sensor from a first position for recording an image to a second position for holding the recorded sensor; and means for conveying the sensor from the second position to a third position. a means for irradiating or heating the sensor with light at the third position to emit the energy stored in the sensor as light and detecting the light to obtain an image signal; a means for conveying the sensor from the third position to a fourth position holding a plurality of sensors; a means for conveying the sensor at the fourth position to the sample image recording section at the first position; and erasing means for erasing information accumulated in the sensor between the position No. 3 and the first position, and the first to fourth positions are arranged in the same vacuum chamber. It is characterized by

[Function] A large number of two-dimensional sensors are independently provided in a vacuum chamber provided at the bottom of a transmission electron microscope barrel.

The two-dimensional sensor that has recorded the electron beam image is stored in the sensor holder before being transported to the information reading position. The sensors whose images have been recorded are successively transported to the holding section and stored therein, and the sensors are transferred from the holding section to the information reading position in accordance with the information reading time.

[Example] An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows a transmission electron microscope which is an embodiment of the present invention, in which 31 is an electron gun, 32 is a converging lens, 33 is a sample, 34 is an objective lens, 35 is an intermediate lens, and 36 is an electron gun. These lenses and the like are arranged in a lens barrel 37 whose interior is evacuated. The electron beam generated from the electron gun 31 is focused by the converging lens 32 and irradiated onto the sample 33, and the electron beam transmitted through the sample 33 is
An image is formed by the objective lens 34. The elephant formed by the objective lens is enlarged and projected by an intermediate lens 35 and a projection lens 36. A vacuum chamber 38 is provided at the bottom of the lens barrel 37.
is provided, and within the vacuum chamber 38, images are recorded, read, etc. by a two-dimensional sensor. The position (A> in the vacuum chamber 38 is the recording position of the image projected by the projection lens 36, and three cassettes into which the stimulable phosphor sheets 1 to 1 are inserted are arranged at the position (A). .

As shown in FIG. 2, the cassette 39 is formed into a frame shape, and is provided with an opening 39a into which a stimulable phosphor sheet is inserted and an opening 39b through which the image recording surface of the sheet is exposed. Further, a large number of holes 40 are bored in the sides of the front and back surfaces of the cassette, into which gears for transporting the cassette are engaged. Note that it is effective to cover the opening 39a with a cover after inserting the sheet to prevent the sheet from falling off.

Referring again to FIG. 1, reference numeral 41 indicates gears for feeding the cassette 39vQ, and although not shown, each gear is connected to a drive mechanism. A holding container 42 for the cassette 39 is arranged at the (B) position of the vacuum chamber 38. When the gear 41 is rotated at the (A) position and the three cassettes are transported in the direction of the arrow, the cassettes are It will fall into the container 42. The position (C) is the reading position of information recorded on the stimulable phosphor sheet, and the sheet in the cassette 39 placed at this position is exposed to the laser beam from the laser beam ff1iTi43 placed outside the vacuum chamber. is reflected by the reflecting mirror 44, transmitted through the light transmission window 45, and irradiated. 46 is a detector that detects fluorescence generated by irradiating the sheet with the light of the sea 11. (D) The position is
This is the position where information recorded on the sheet is erased, and the sheets in the three cassettes placed at this position are equipped with a light source 4.
Light is emitted from 7. 48, the light from the light source 47 is (C
) This is a screen that blocks light so that it does not shine onto the sheet on which information is being read at position n.

49 is an endless belt that conveys the cassette 39, and this belt is moved by the rotation of the roller 50. The cassette 39 transported by the movement of the four belts is
It is placed on the support stand 51 at position (E). The cassette on the support base is moved to the first position (F) by the transport mechanism 52.
is stored in a cassette storage container 53. At position (G), the first cassette storage container 53 and the second cassette storage container 53
A cassette storage container 54 is arranged.

The first and second cassette storage containers can store a large number of cassettes therein, and the three cassettes inside are stored on a support plate 56 that is constantly pressed upward by a spring 55. The first and second containers 53 and 54 are ([
) position and the (G) position, and an opening is provided at the top of each container so that the light from the light source 57 is irradiated onto the sheet at the (G) position. It is being 58 is a screen for blocking light from the light source 57 from being irradiated onto the sheet at the <A) position.

In the above configuration, the upper cassette 39 in the container 54 is moved to (A) by the rotation of the gear 41 at the (G) position.
) position. At this (Δ) position, the electron beam is projected onto the stimulable phosphor sheets inserted into the three cassettes, and image information is recorded on the sheets. The cassette 39 on which the recording has been completed is conveyed into the force cellar holding container 42 at position (B) by the rotation of the gear 41. (G)
The transport of the cassette from the position (A) to the position (A) and the transport of the cassette from the position (A) to the position (B) are performed one after another in accordance with the image recording time. Stores recorded cassettes. The lower cassette in the container 42 at the (B) position is conveyed to the (C) position by the rotation of the gear 41, and at this (C) position, recorded information is recorded by laser beam scanning and fluorescence detection. is read. The cassette that has finished reading the information at position (C) is transported to position (D) and is placed at the light source 4.
The recorded information is erased by being irradiated with light from 7. The cassette whose information has been erased at the position (D) is conveyed to the right side in the figure by the rotation of the gear 41.
Fall onto 4 endless belts. The four belts move in the direction of the arrow, and the cassettes on the belt are conveyed onto the support plate 51 at position (E). The cassette transported to the (E) position is lifted by an appropriate chuck mechanism included in the transport mechanism 52, and is transported toward the cassette storage container 53 at the (F) position and stored therein. (G
) position in the second cassette storage container 54 is
After secondary erasing of information is performed by the light from the light source 57, the cassettes are transported one after another to the (A) position. When all the cassettes in the container 54 are transported to the (A) position, the container 54 is (
Moved to F) position (E) position! A first container 53 that stores the cassette from δ and conversely stores a large number of cassettes.
is moved to the (G) position and waited for image recording. Although detailed explanation was not provided, the drive of each gear is controlled by a computer while detecting the state of the cassette at each position using appropriate sensors.

Although the present invention has been described in detail above, the present invention is not limited to the embodiments described above and can be modified in many ways. For example, although the description has been made using a stimulable phosphor sheet, a thermophosphor sheet may also be used. Furthermore, although the secondary erasing of information stored on the sheet is performed at the (G) position, it may also be configured such that the secondary erasing is performed between the (G) position and the △) position. Information may be deleted only once. Furthermore, the cassette can be transported by means other than gears or belts. Furthermore, when recording a large number of images in succession, it is possible to increase the number of recorded cassettes held by providing a plurality of cassette holding containers 42 at the position (B), and furthermore, it is possible to increase the number of recorded cassettes held. Laser oscillator to speed up reading.

A plurality of reading mechanisms including laser beam scanning means, fluorescence detectors, etc. may be provided.

[Effects] As detailed above, in the present invention, a holding position for holding the recorded sensor is provided between the position where information is recorded on the two-dimensional sensor and the position where the information recorded on the sensor is read. Images can be continuously recorded on the sensor at high speed regardless of the reading of information.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a transmission electron microscope which is an embodiment of the present invention, FIG. 2 is a diagram showing a cassette used in the embodiment of FIG. 1, and FIG. 3 is a cross-section of a stimulable phosphor sheet. FIG. 4 is a diagram showing a conventional transmission electron microscope. 31... Electron gun 32... Converging lens 33
...Sample 34...Objective lens 35...
・Intermediate lens 36... Projection lens 37... Lens barrel 38... Three vacuum chambers... Cassette
41...Tooth count 42...Holding container 4
3...Laser oscillator 44...Reflector 45
...Light transmission window 46...Detector 47...
Light source 48...Screen 49...Belt 50
...Roller 51...Support stand 52...Transportation mechanism 53...Storage container 54...Storage container 55...Spring 56...Support plate
57...Light source 58...Screen

Claims (3)

[Claims] (1) A means for enlarging and projecting a sample image, a two-dimensional sensor for accumulating and recording the projected sample image, and holding a recorded sensor from a first position for recording the sample image on the two-dimensional sensor. means for transporting the sensor to a second location;
a means for transporting the sensor from the position to a third position, and at the third position, irradiating or heating the sensor with light to release the energy accumulated in the sensor as light, and detecting this light. means for obtaining a video signal by
means for conveying the sensor from the third position to a fourth position holding a plurality of sensors; and means for conveying the sensor at the fourth position to the sample image recording section at the first position; The third
and an erasing means for erasing information accumulated in the sensor between the position of electronic microscope. (2) The erasing means is constituted by a primary erasing means and a secondary erasing means, the primary erasing means is disposed between the third and fourth positions, and the secondary erasing means is located at the first 2. A transmission electron microscope according to claim 1, wherein the transmission electron microscope is arranged so as to erase information stored in the sensor facing the position. (3) The transmission electron microscope according to claim 1, wherein the sensors are each held in a cassette.