Abstract: The front wheels of the vehicle having an adjustable wheel base are joined to the front portion of a main frame, on which a vehicle seat is mounted. The upper ends of a pair of rotating arms are rotatably joined to the main frame. The lower ends of the rotating arms are rotatably joined to the rear wheels. The upper arms and the lower arm are provided rotatably connected together such that the main frame and the rear wheels are joined at the back of the rotating arms. The operating portion of the operating apparatus, on which the main frame is installed, is joined via the operating links to the rotating arms. By operating the operating apparatus, the rotating arms are rotated by the operating links and the rear wheels are moved with respect to the front wheels. Simultaneously, the inclination of the main frame is changed.

Abstract: A vacuum container is evacuated to be kept at an ultra-high vacuum. Valve means is provided for connecting and disconnecting the inside of the vacuum container with and from the outside thereof, and includes a vacuum-tight seal made of a high polymer having a water absorptivity of 0.1% and less and an outgassing rate of 2.times.10.sup.-6 (Torr.multidot.l/sec/cm.sup.2 :at 200.degree. C.) and less.

Abstract: A specimen is scanned with an electron beam so as to generate a signal characteristic of the specimen to thereby produce an image thereof on the basis of the generated signal. A memory is provided for storing operating conditions of a scanning electron microscope which are associated with identification information for specifying the specimen. The identification information is designated so that thereby at least one operating condition corresponding to the designated identification information is read out from the memory, and the read out operating condition is automatically set so that the scanning electron microscope is operated under the set operating condition.

Abstract: A scanning tunnel microscope comprising: a SEM stage provided in a specimen chamber of a SEM and having a mechanism for moving in a two dimensional manner along a surface perpendicular to an electron beam; a specimen stage provided on the SEM stage and provided with a mechanism for holding a specimen so that a surface of the specimen makes an angle of 45.degree.

Abstract: A sample is mounted on a support table adjacent a probe of a scanning tunnelling microscope, the support table permitting the sample to move relative to the probe. The probe is also movable in a direction generally perpendicular to the sample surface, between a withdrawn position and a scanning separation. A scanning electron microscope is located adjacent the sample and probe, and its electron beam scans both the sample and the probe and generates an image on a display from electrons from the sample detected by a detector. In order that that operator can position the probe on a target of a sample, for scanning by the probe, a marker is generated on the display by a graphics display unit, which marker indicates the probe-to-sample separation and preferably indicates the probe-to-sample approach point and the direction of movement of the probe towards the sample.

Abstract: The present invention relates to an apparatus for detecting the secondary electrons which are obtained from a sample (4) when the sample is irradiated with an electron beam (2). When this electron beam (2) is subjected to a low acceleration voltage, it is desirable to detect the secondary electrons efficiently without interfering with the deflection of the electron beam (2). In order to solve this subject matter, there is used a means (7) for generating an electric field and a magnetic field which are so perpendicular to each other that they apply deflecting forces in the direction common to the secondary electrons while applying no deflecting force to the electron beam as a whole.

Abstract: An electron producing apparatus of the field emission type wherein instantaneous values of an emitted current are sequentially measured to store a relative minimum value of the emitted current which is obtained in such a manner that one instantaneous value which is stored is then replaced by another instantaneous value which is even smaller in magnitude than the previously stored one, and at the same time the instantaneous values are sequentially compared with the stored relative minimum value so that the electron producing apparatus is deenergized when an instantaneous value assumes a certain magnitude relative to the stored relative minimum value.