JP6749544B2 - cover - Google Patents

Description

The present invention relates to a sample holder cover, and more particularly to a sample holder cover used in an electron microscope.

Generally, the following five factors can be considered as what should be noted as an installation environment that affects the resolution and image quality of an electron microscope.

1. Room temperature change A change in the room temperature where the electron microscope is installed affects the power supply, goniometer or holder, causing misalignment of the electron beam or drifting in the holder or goniometer. Normally, at room temperature where the electron microscope is installed, it is necessary to keep the temperature constant by operating air conditioning equipment such as an air conditioner for 24 hours 365 days.

2. Noise/Vibration For example, if there is a noise source near an electron microscope such as a transmission electron microscope (hereinafter referred to as “TEM”), noise will be included in the image acquired by the TEM. For example, if you clap your hand, the image will shake for a moment. Even if the vibration such as clapping hands is not usually taken into consideration, the sound of a cooling fan attached to another device or the sound of a pump may be a vibration source. Further, as a vibration source, a pump or a car running outside (a truck, especially when there is a large road nearby) also becomes a vibration source. The vibrations from these vibration sources also shake the TEM image, which hinders accurate and clear image acquisition. Therefore, by taking measures such as not placing a noise source near the TEM and not placing an electron microscope near the road in the first place, all noise and vibration are excluded as much as possible when acquiring TEM images. There is a need to.

3. External magnetic field Electric field If there is an electric wire or fluorescent lamp near the TEM, the vibration of the electromagnetic field causes the electron beam to sway or bend, resulting in a significant reduction in the resolution of the TEM. A magnetic stirrer in the next room (liquid stirring device that uses magnetic force) or an elevator in the same building may cause the electron beam to move due to changes in the magnetic field. As a countermeasure against this, the influence of the external magnetic field can be eliminated by surrounding the electron microscope with a magnetic field canceller.

4. Pressure difference (pressure fluctuation)
When the door is opened or closed, the atmospheric pressure inside may change due to the atmospheric pressure outside. The sample position is not constant because the TEM holder is pushed or pulled by the change in atmospheric pressure. That is, sample drift occurs. For such disturbances around the TEM, there are products in which the electron microscope itself is covered with an enclosure such as a box, and various measures have been taken to reduce the influence of the disturbance.

5. The temperature inside the room is kept constant by air-conditioning equipment such as an air conditioner, but if the air conditioning air blows directly on the electron microscope body and holder, the electron microscope and sample holder will be shaken. Even if it does not hit directly, it may be affected by a large air flow. Further, the sound of the air conditioner compressor also becomes the above-mentioned noise and vibration source. By making a detour so that the wind does not hit it directly, or by using the gonio cover or enclosure introduced in Section 4 above, it is possible to reduce these effects.

As described above, the installation condition of the electron microscope including the TEM needs to satisfy several environmental factors as described above, and thus the location is often selected. Usually, engineers of microscope manufacturers measure the environment of the installation place in advance, and from information from users, determine whether the place (room) is an environment sufficient for the performance of the device. The installation environment may change due to lack of information from the user, addition of devices to the same room later, or disturbance from an adjacent room. Since it is a well-known fact that the installation environment affects the resolution and image quality of the electron microscope, the current situation is that electron microscope experts are very concerned about changes in the environment.

For example, as an example of a type of cover that covers the entire apparatus, the apparatus main body having at least a scanning electron microscope for acquiring an image of a sample, and a cover arranged around the apparatus main body, the natural frequency of the apparatus main body, Alternatively, a charged particle beam device is known in which a sound absorber having a frequency of an acoustic standing wave generated inside the cover in a sound absorption frequency band is provided inside the cover (Patent Document 1). ..

JP 2012-104298 A

However, a relatively large-scale enclosure such as the above-mentioned Patent Document 1 that covers the entire apparatus has a problem that the apparatus is large-scale and costly. For example, since all accessories such as a mechanism for moving a sample such as an actuator are housed in the cover, it is necessary to remove the entire cover at the time of maintenance, and there is a problem that maintainability is poor. Therefore, there is a demand for a device that can improve the maintainability while solving the above problems.

Therefore, in order to solve the above problems, it is an object of the present invention to provide a compact cover that can reduce sound and vibration easily.

In order to achieve the above object, the present inventor has found the present invention as a result of extensive studies on the cover.

That is, the cover of the present invention is a cover that includes a cover part that covers a part of the sample holder, and a sound/vibration reduction part that is provided in the cover part and that reduces sound and vibration. It is characterized by having a connector portion provided on the cover portion for connecting a cable extending from the sample holder .

Further, in a preferred embodiment of the cover of the present invention, the cover portion is attached to a part of a housing of the electron microscope or a part of an outside of the goniometer.

Further, in a preferred aspect of the cover of the present invention, the sound/vibration reducing unit is configured to generate sound/vibration having a phase opposite to that of the sound/vibration.

A preferred embodiment of the cover of the present invention is characterized by further including a wireless receiver.

A preferred embodiment of the electron microscope of the present invention is characterized by including the cover of the preferred embodiment of the present invention.

According to the cover of the present invention, the cover portion first absorbs conversations outside the cover (or at the place where the electron microscope is installed) and sound/vibration (noise) from peripheral devices, and reduces the adverse effect of noise on the sample holder. It has the advantageous effect. Further, according to the present invention according to another embodiment, an advantageous effect that the influence of noise can be further reduced by adding a noise canceller to the cover is exerted. In addition, according to the cover of the present invention, when the degree of sealing of the cover is increased, it is less susceptible to room temperature and atmospheric pressure fluctuation, which is a further advantageous effect.

FIG. 1 is a side sectional view of a cover according to an embodiment of the present invention.

The cover of the present invention includes a cover part that covers a part of the sample holder, and a sound/vibration reducing part that is provided in the cover part and that reduces sound and vibration. For example, when the sample holder is installed in the electron microscope, the cover part that covers a part of the sample holder can be installed not in the housing of the electron microscope but mainly in a portion exposed to the external environment. This is because the cover portion is mainly for reducing sound, vibration and the like from the external environment. The cover of the present invention may include a sound/vibration reducing section that is provided in at least a part of the cover section to reduce sound and vibration, as described later. Although the sound/vibration can be reduced also by the cover portion, in the present invention, a sound/vibration reducing portion having a higher effect than the sound/vibration reducing effect of the cover portion can be further provided.

Regarding the effect of vibration absorption by the cover itself, it is considered that, for example, the influence of the degree of speaking voice and the sound transmitted through the air of the surrounding pump and compressor can be removed. At this time, considering how it affects the microscope image, if there are many vibration sources around the image, the image will be slightly blurred or noisy during high-resolution observation, but if a cover such as a gonio cover is installed, noise will jump. Decrease and the image becomes clear.

Further, in the present invention, the material of the cover is not particularly limited. For example, the cover part may be made of a relatively lightweight material (for example, a light resin, a light metal, etc.) in consideration of the load on the part to which the cover part is attached. Assuming that the cover is attached to a part of the housing of the electron microscope or a part of the outside of the goniometer, the material of the cover is made of light resin, in the case of metal it is made of light aluminum in order to reduce the load on the goniometer etc. Etc. can be mentioned.

The sample holder is used for an electron microscope such as a transmission electron microscope (TEM). The sample holder is not limited to the electron microscope and may be used for an apparatus for observing the sample and acquiring an image of the sample.

In the present invention, a sound/vibration reducing unit that reduces sound and vibration can be provided from the viewpoint of further reducing the influence of disturbance such as sound and vibration. In a preferred aspect of the cover of the present invention, the sound/vibration reducing unit may generate sound/vibration having an opposite phase of the sound/vibration. The installation position of the sound/vibration reducing unit is not particularly limited. For example, it may be provided in the range of the connector portion described later. Further, the sound/vibration reducing section may be provided on the cover section via a hermetic structure.

Further, in a preferred embodiment of the cover of the present invention, the cover portion is attached to a part of a housing of the electron microscope or a part of an outside of the goniometer. However, if it is possible to cover a part of the sample holder, the position where the sample holder is attached need not be limited to a part of the housing of the electron microscope or the like, or a part of the outside of the goniometer or the like.

The method of attaching the cover of the present invention is not particularly limited. For example, when the hinge is attached to a part of the outside of the goniometer, if it has a hinge, the existing hinge may be used for attachment. The cover can be designed according to the housing and goniometer of the electron microscope. Furthermore, an attachment of another member may be used, or an arbitrary attachment mechanism such as a fitting type may be adopted. The attachment may be produced and attached to the cover of the present invention, or conversely, the attachment of the present invention may be attached to the attachment and separately prepared attachments to various electron microscope casings and goniometers. ..

Further, in the present invention, a means for maintaining airtightness inside the cover (for example, a seal member, an O-ring, a packing, etc.) may be interposed between the cover portion and the portion to which the cover portion is attached.

Further, in the present invention, a pressure relief portion may be provided on at least a part of the cover portion. This is for safety when the cooling holder is used, because the liquid nitrogen evaporates and the pressure inside the cover rises. An example of the pressure relief portion is a valve having airtightness.

Further, a preferred embodiment of the cover of the present invention is characterized in that it further comprises a connector portion provided on at least a part of the cover portion for connecting a cable extending from the sample holder. By having the connector portion, it is possible to eliminate the need for a hole for passing the cable through the cover. Further, the connector portion may be provided with a hermetic (airtight sealing structure, hermetic connector, etc.) including a portion for connecting the cable and its periphery.

Depending on the type of sample holder (for example, heating, electric field, magnetic field, gas introduction), a controller is essential for parameter control, and it is necessary to connect the controller and the holder with a cable. When the cable is connected to the holder, the holder vibrates and reduces the resolution. Further, if the cover that can be attached so far cannot be closed due to the cable, the image acquisition by the TEM becomes vulnerable to environmental changes. Here, in the existing technology example, a device is provided in which a hole through which a cable can be inserted is formed in a cover having an appropriate size and the cable is inserted there. However, in the conventional method, the sealing degree of the cover is lowered, and the problem of vibration transmission from the cable still remains. Further, even if the cover is simply attached, the noise cannot be completely prevented, and some sample holders may be affected by noise from the outside of the cover.

On the other hand, in the present invention, since the connector can be used, it is possible to eliminate the problem of vibration transmission. Further, since the connector is used, unlike the case where the hole is simply provided, the airtightness can be secured.

In a preferred embodiment of the cover of the present invention, the cover is further provided with a wireless receiver. The wireless receiver can be installed on any part of the cover, and the cover of the present invention is not particularly limited as long as it has the wireless receiver. For example, the connector section may be provided with a radio receiver, or, for example, when the connector section includes a hermetically attached to the cover section, the connector section may be attached to the radio receiver in the same hermetically, and the radio receiver may be attached. It may be incorporated into the cover part together with the sound/vibration reducing part. For example, it is possible to incorporate a sound/vibration reducing unit (also called a noise canceller) and a wireless receiver together. The effect of the radio receiver can be literally wireless, so that, for example, vibrations from the cord can be blocked by almost 100%. At this time, a storage battery (for example, a lithium ion battery or the like) can be attached to the goniometer to operate the drive system of the holder.

An electron microscope according to a preferred embodiment of the present invention is characterized by including the cover according to any one of the preferred embodiments of the present invention. The electron microscope provided with the cover of the present invention can remove more disturbance and can provide more accurate observation.

Hereinafter, embodiments of the cover of the present invention will be described with reference to the drawings, but the present invention is not construed as being limited to these embodiments. Further, it goes without saying that appropriate changes can be made without departing from the gist of the present invention.

FIG. 1 is a diagram showing a cross-sectional view of an example cover 100 according to an embodiment of the present invention. FIG. 1 shows a goniometer 10, a cover portion 20, a noise canceller 30, a hermetic 40, a connector 50, a cable 60, a sample holder or a TEM holder 70, and a housing 80 of an electron microscope.

The cover portion 20 of the cover 100 is detachably attached to a part of the outside of the goniometer 10 of the electron microscope. The method of attaching the cover 20 may be an attachment of another member (not shown) or a fitting type structure, and is not particularly limited. On the other hand, regardless of the mounting method, in order to maintain the airtightness inside the cover, it is preferable to dispose a seal member between the cover 20 and a part of the outside of the goniometer 10. Examples of the seal member include, but are not limited to, O-rings and packings.

The material of the cover 20 attached near the goniometer may be appropriately selected from resin, metal, etc., as long as it is relatively lightweight in consideration of the load applied to the attachment site, and is not particularly limited.

The goniometer 10 is built in a part of the casing 80 of the TEM and supports the sample holder 70. In this embodiment, the sample holder 70 and the cable 60 extending from the sample holder 70 are located inside the cover 100 attached to the goniometer 10.

The noise canceller 30 is one of specific examples of the sound/vibration reducing unit. The noise canceller 30 can employ a technique of generating a signal having an opposite phase to the sound/vibration (noise) outside the cover 100 to reduce or invalidate the noise. With the cover 100 itself, in addition to attenuating noise from the outside of the cover 100, the noise canceller 30 can significantly suppress a component of such noise passing through the cover 100.

The number and position of the noise cancellers 30 attached to the cover 20 are not particularly limited within the range of the noise suppression effect. In the example shown in FIG. 1, the noise canceller 30 is provided on the hermetic 40 having the connector 50, but the present invention is not limited to this.

The hermetic 40 is also an airtight sealing member that shields the inside of the cover 100 from the outside air. As shown in FIG. 1, the noise canceller 30 and the connector 50 may be attached to one hermetic 40, or the hermetic of the noise canceller 30 and the hermetic of the connector 50 may be independent parts.

The electron microscope includes a controller (not shown) for controlling the parameters of the sample holder. The cable 60 is a member for connecting such a controller and the sample holder. In the cover 100 illustrated in FIG. 1, the cable 60 extends between the sample holder 70 and the connector 50. One end of the cable 60 is connected to the sample holder 70, and the other end is connected to the connector 50. By providing the connector 50 on the cover portion 20, vibration is not transmitted to the sample holder 70 directly or to the extent that it does not interfere with sample observation. Since the connector 50 does not have a hole through which the cable 60 is passed, the degree of sealing achieved by the cover 100 is further improved as compared with a conventional cover or the like. When the degree of tightness is improved, the influence of the pressure difference on the sample holder is further reduced, and the observation of the sample by the electron microscope becomes more difficult to be affected by the room temperature and atmospheric pressure fluctuation.

The cover 100 may be further provided with a wireless receiver (not shown) that supplies electric power with a battery (rechargeable). The wireless receiver may be provided in the connector 50, in the vicinity of the connector 50, or in the noise canceller 30, for example. The radio receiver may also be such that the noise canceller 30 and the radio receiver are integrated in the area of the hermetic 40. With such a radio receiver, since the outside of the cover 100 is wireless, vibrations from the outside of the cover 100 can be blocked to the extent that there is no problem at least in a practical range.

When the wireless receiver is used for wireless outside the cover 100, it may be necessary to attach a storage battery (for example, a lithium ion battery) to the goniometer in order to operate the drive system of the sample holder.

Further, by removing the noise canceller 30 and the connector 50 so that the connector 50 can be replaced, the noise canceller 30 and the connector of various shapes, types, and specifications may be replaced.

Further, when the cooling holder is used as the sample holder 70, the rise of the pressure inside the cover due to the evaporation of liquid nitrogen is considered. For safety against this pressure increase, a pressure relief portion (for example, a valve) may be added to the cover of the present invention. Even when such a pressure relief portion is added, it is preferable that the airtightness of the cover 100 can be maintained.

Further, a soundproofing/sound absorbing means may be further provided inside the cover. More specifically, for example, a sponge, a porous member, or coating can be used as the soundproof/sound absorbing means.

According to the cover of the present invention,
1. The cover first absorbs conversations outside the cover (or at the place where the electric microscope is installed) and sounds/vibrations (noise) from peripheral devices, and reduces the adverse effect of noise on the sample holder.
2. The effect of noise can be further reduced by adding a noise canceller to the cover.
3. In another embodiment in which a connector is provided on the cover, noise is not directly transmitted to the sample holder, and if a hole for passing a cable through the cover is not required, the inside of the cover is more tightly sealed and the pressure difference between the inside and outside of the cover is increased. The effect of can be reduced.
4. When the degree of airtightness of the cover is increased, it is less likely to be affected by room temperature or atmospheric pressure variation, which is a more advantageous effect.

As described above, according to the present invention, by attaching a cover to a part of the apparatus, it has become clear that it is possible to protect the electron microscope main body and the holder from changes in the external environment such as temperature and vibration.

The cover of the present invention enables stable observation in high-precision visualization, image formation or analysis of a sample, and can be expected to make a great contribution to research progress.

10 Goniometer 20 Cover 30 Noise Canceller 40 Hermetic 50 Connector 60 Cable 70 TEM Holder 80 Electron Microscope Housing 100 Cover

Claims (5)

A cover provided with a cover part for covering a part of a sample holder, and a sound/vibration reducing part provided in the cover part for reducing sound and vibration , the cover being provided in the cover part. A cover having a connector portion for connecting a cable extending from the sample holder . The cover according to claim 1, wherein the cover is attached to a part of a housing of an electron microscope or a part of an outside of a goniometer. The cover according to claim 1 or 2 , wherein the sound/vibration reduction unit generates a sound/vibration having a phase opposite to that of the sound/vibration. The cover according to any one of claims 1 to 3 , further comprising a wireless receiver. An electron microscope comprising the cover according to claim 1.

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